PC

Roger Cheng

First Few Weeks With Dell Latitude 9410

Shortly after I bought an off-lease Dell Latitude 9410, I opened it up to verify everything met expectations. After finding no deal-breakers, I buttoned it back up and I’ve been using it for a few weeks. I’m happy with my purchase, here are some notes:

Intel Core i7

The Core i7 processor in my 9410 gives me snappy and responsive performance when I want it, then throttle itself down for low power consumption when I don’t. This means I get useful battery life on par with power-frugal Intel Atom machines, yet never feel sluggish during demanding times like I would with an Atom-based machine. My typical usage pattern results in 4-6 hours of runtime even with just 80% charge (more on that below) which ranks favorably among my past Intel-powered laptops. However, it falls short of my Apple MacBook Air with M1 Apple silicon. Both machines deliver snappy performance, but the M1 never gets as hot and runs far longer on battery.

The power and heat situation is a tradeoff against benefits of having an Intel CPU. All my developer tools are available here. I can run Docker containers without worrying about whether I need to find an ARM64 build. And pretty much every random USB peripheral will have Windows drivers. The biggest stumble so far is dual-booting Windows/Ubuntu: Dell configured this machine with Intel RST, and Ubuntu chose not to play well with RST. There are several possible solutions to this problem. I just haven’t been motivated enough to implement any of them yet.

Tablet/Laptop Convertible

Another thing my MacBook Air can’t do is fold its screen around and turn into a tablet. This was a deliberate design decision by Apple, who chose to keep MacBooks differentiated from iPads. After living with a Windows convertible for a few weeks I’ve decided I’m a fan. I’ve used Windows convertibles before but they’ve all been budget machines with limited hardware that hampered my user experience. This was my first full-power convertible and it means I can finally enjoy the benefits of a transformer and not trip over tradeoffs at every turn.

It’s nice to be able to switch back and forth. This is most useful when I’m reading documentation for software tools. I can switch to laptop mode to type a few commands for a quick hands-on exercise, then return to tablet mode and continue reading. With this positive experience I am much more receptive to such machines in the future, but I’m still not willing to pay the large price premium usually associated with such capability. Buying off-lease secondhand machines is likely to remain my pattern.

Power And Charging

Like my M1 MacBook Air, the 9410 charges via a USB Type-C connector instead of a proprietary power plug. However, this doesn’t necessarily mean I can use any USB-C power source. When up and running it demands 60 Watts. (USB power meter says 20V @ 3A.) This is even more demanding than the M1 MacBook Air, which is happy with 45W. If I plug in a less powerful USB-C supply, the MacBook will alert me that battery is still draining though at a slower rate. In contrast, this Dell would refuse to accept any power at all.

Fortunately, there are two charging systems on every laptop: there’s an operating system driver when the laptop is on, either running or in low-power sleep mode. Then there’s a completely separate firmware-based mechanism when the laptop is off, either in hibernation or completely shut down. Dell’s firmware-based charging system is willing to accepting power from sources that can’t deliver 60W. So if the bundled 60W power adapter fails or if I lose it, I still have alternatives.

And finally: like my Dell Inspiron 7577, there is a BIOS setting for me to restrict battery charging percentage. I set mine to stop charging at 80%. That still deliver enough battery runtime for most of my usage sessions, and avoiding charging to 100% should improve battery longevity. I can always change that setting back to 100% if I ever need extra runtime.

Whether iPad?

I justified this purchase as an alternative to upgrading my soon-to-be-obsolete 6th gen iPad and for my usage it was a success. At the moment I can imagine only two reasons why I might still want an iPad. The first is weight. Three pounds is light for a laptop but that’s triple the weight of an iPad. In practice, this hasn’t been a huge problem as I don’t like holding things up by hand for long periods of time, whether one pound or three. The second differentiator is the Apple app store, but at the moment I don’t need any iPad app exclusives. Maybe something else would arise as motivation for spending several hundred dollars? Until I encounter such motivation, I expect to be well-served by this Dell Latitude 9410.

Roger Cheng

Dell Latitude 9410 Internals: M.2 2280 Confirmed

Buying an used off-lease computer means giving up shiny-new cosmetic perfection in exchange for a hefty discount, a tradeoff I was willing to make. I don’t think I’ll be bothered by the “Grade B” blemishes on my unit and besides, it’s what’s inside that really counts. Purchasing from Dell Financial Services via their retail site https://dellrefurbished.com includes a 100-day warranty to back up their claim that all machines are fully functional regardless of cosmetic state.

My order confirmation email had a pleasant unexpected bonus: it included the Dell service tag for the specific machine I had just bought. I could then put that service tag into Dell’s support site to learn information about that specific unit before it had even arrived. There were still a few weeks left on its original 3 year warranty, though it would expire before the 100 day refurbished warranty would. Another positive attribute was the fact my unit was not equipped with a cellular data (WWAN) module. I don’t expect to use WWAN, and without the module, the machine should have room for a M.2 SSD in the more common, longer, and cheaper 2280 form factor. The factory configuration list included a model number for the factory SSD, which is associated with a M.2 2280 drive.

The machine arrived a few days later and, once I confirmed the machine functioned as expected, I brought up Dell’s service manual and opened up my unit to familiarize myself with its internals and to confirm information listed on Dell support. Compared with my previous Dell laptops, there was much more extensive use of thin adhesive-backed sheets of various materials. Are they for RF shielding? For airflow management? Other purposes? It’s hard for me to tell but their presence is not surprising in a device designed to be thin and light. I just have to keep in mind I can only remove them a few times before their adhesive gives out.

Modern component miniaturization allowed smaller circuit boards, freeing up more internal volume for the battery. Which needs to be disconnected and the system depowered before I disconnect anything else. This battery plug was very securely fastened and difficult to remove. Far more difficult than any previous Dell laptop battery connectors I’ve encountered. Hard enough that I triple checked I didn’t overlook some other mechanism I was supposed to release before unplugging the connector. But there were no other mechanisms, it was just a really tight fit.

After the system was depowered, I quickly made my way to the SSD to confirm it was indeed a M.2 2280 unit. This will make future upgrades easier and cheaper than the less common M.2 2230 type used in WWAN-equipped units. Speaking of which, I don’t think I can (easily) retrofit mine with one. The module connector is there on the logic board, but I don’t see any loose wires that would be appropriate for plugging into a cellular modem. So my machine probably lack cellular antennae as well. Though if I ever come into possession of a M.2 2230 SSD in the future, I might be tempted to give it a shot anyway for curiosity’s sake. Compatible WWAN modules seem to cost about $30-$50 from various Amazon vendors and maybe I can rig up a less elegant antenna. As long as I keep my expectations modest for such a project, it might still be an interesting data point. In the meantime I’m content to use the machine as-is.

Roger Cheng

Dell Latitude 9410 Cosmetic Grade B

I’ve decided to buy an off-lease Dell Latitude 9410 from Dell Financial Services, via their retail web site https://dellrefurbished.com. All of the machines have been evaluated to be in good functional order, but some of them have cosmetic blemishes separated into cosmetic grades. Cosmetic grade A are for machines in good shape, and grade B indicate machines that are in… less good shape at a lower price. Since I’m a cheapskate, I ordered a grade B unit and in my specific case, it wasn’t bad at all!

When the machine arrived, my first surprise was the label at the bottom: “Refurbished to Dell specifications by FedEx Supply Chain” I expected the evaluation and refurbishment process to be done by a Dell subcontractor, I just didn’t expect to see the FedEx name. Prompted by this surprise, I did a bit of research to find FedEx TechConnect, with uncertain relationship to “FedEx Supply Chain” formerly GENCO. To me it seems like an odd side gig for FedEx to take on, but I’m not a MBA at FedEx business development.

I found some damage on the keyboard. It means the backlight would shine through these damaged corners, not something I’d notice while I’m typing and looking at the screen. This damage is not a surprise in hindsight: when the screen is flipped around to turn this into a tablet, its keyboard becomes the exposed bottom of the device. The previous user of this laptop must have set the tablet down on something that caused this key cap damage.

Another problem with this device was the rubber strip at the bottom: it’s gone. There’s supposed to be a layer of light gray soft material overmolded onto this hard black plastic core strip. With the soft layer gone, all I have is this ugly looking strip. Fortunately I don’t have to look at it when I’m using the laptop. As a substitute, the refurbish process added cheap square stick-on rubber feet.

The stick-on squares are much thicker than the missing rubber strips. In laptop mode, this meant a larger gap at the bottom for better air cooling. But the thickness gets in the way when I fold the screen around for tablet mode: I couldn’t fold the screen completely flat when these thick rubber pads are in place. I will look for slightly thinner stick-on rubber feet to replace these thick squares, with the goal of restoring full tablet mode form factor while preserving laptop mode air cooling. I consider this a minor detail that is within my ability to fix, and not a big deal.

I found no noticeable damage on the screen, the metal body, or lid. Those were bigger concerns buying “Grade B” and my unit is practically pristine on those fronts. I don’t think the slightly scratched keyboard would bother me very much, and I can replace the stick-on rubber feet. I’m perfectly happy accepting those blemishes in exchange for >80% discount off original MSRP, especially when its internals look perfectly fine.

Roger Cheng

Dell Latitude 9410 2-in-1 Laptop/Tablet Convertible

When I learned I will need to replace my iPad in the near future, I saw an opportunity to give the Windows laptop/tablet convertible concept another try. My earlier encounters were marred by bloatware, or weighed too much for a practical tablet. A secondhand Acer Aspire Switch 10 worked admirably well but it was still heavily constrained by its modest hardware. I had been curious to see what the form factor is capable of in a modern sleek lightweight powerhouse. Getting one means paying a lot of money to buy new, which I was unwilling to do. But now that I can buy a heavily discounted off-lease unit from https://dellrefurbished.com, I’m going to give that a try.

I started keeping an eye on the “Tablets and 2-in-1 Laptops” section of the site. Batches of various machines came and went. Low end offerings are built around humble Intel Atom processors. They go up through high end machines with Intel Core i7 CPUs. I would pull up Dell’s specifications for various model numbers and eventually started focusing on a high-end model that came through with some regularity: Dell Latitude 9410. When new, these cost in the ballpark of two thousand dollars, and frequently end up in the hands of senior corporate executives as much a status symbol as productivity tool. Now they are listed for around $700, which is a decent price for its capabilities. But if I can get one with a 50% discount code, that would bring it down to $350. Over 80% discount from original MSRP and exactly the cost of a new 10th generation Apple iPad.

Latitude 9410s that come through dellrefurbished are pretty well equipped. Usually a CPU from Intel’s Core i7 line, and usually with 16GB of memory and 256GB or 512GB SSDs for storage. The touchscreen has 1920×1080 Full HD resolution, mounted on a double-jointed hinge that allow the user to fold the screen all the way around for a tablet-like form factor. All this in a package that weighs in the ballpark of 3 pounds. As is typical of Dell machines, there is a service manual available showing its internals. I was mildly disappointed to see its memory chips are soldered to the board and could not be upgraded, but at least SSD storage uses standard M.2 NVMe form factors. Units with cellular data (WWAN) modems are constrained to short M.2 2230 SSD. Units without WWAN have room to use M.2 2280 SSD which are more common.

Contemporary reviews say the Latitude 9410 is a very capable machine in a great form factor but came at a very high price. Well, dellrefurbished discount code can solve that last part, but why would they need to discount so heavily to move inventory? My conjecture is that, while this is a great Windows laptop/tablet, it doesn’t exist in a vacuum. The Latitude 9410 was launched in 2020, and what else launched around the same time? Apple’s M1 that caught Intel flat-footed. Apple Silicon launch had all the buzz in tech press, soundly beating equivalent Intel chips in power efficiency. Either more processing power at the same level of electrical power consumption, or far lower electrical power consumption at the same level of computation power. Apple laptops with the M1 chip have battery life that puts Intel-based machines to shame. Four to six hours of battery runtime isn’t bad for an Intel CPU laptop, comparing well to those that came before. But they look pretty sad next to all-day (or even multi-day) use people get out of Apple Silicon laptop battery. This and many other advantages of Apple’s 2020 laptops meant the Latitude 9410 had stiff competition both as useful tool and as status symbol.

Now in 2024, people who want to spend a few hundred dollars on a few-years-old used laptop might be more inclined to look at old Apple Silicon machines instead of an Intel-based Latitude 9410. If so, that would explain why Dell Financial Services has to discount them heavily to find buyers. Whether my conjecture is correct or not, the fact is I can now get a great deal on what used to be Dell’s top-of-the-line Windows laptop/tablet convertible. Especially if I’m willing to accept some cosmetic flaws.

Roger Cheng

Windows Convertible As iPad Replacement

I recently learned that Dell Financial Services operates a site to sell their off-lease computers. And even better, they’re willing to crank up discounts to move inventory. I spent a few fun weeks window-shopping their machines for sale, ranging from super tiny thin clients that bolt to the back of a monitor up to beefy servers designed for a data center equipment rack. But I have no real need to buy a computer. I’ve got my XPS 8950 desktop for gaming and VR. I’ve got my laptop for portable computing. I’ve got an old machine running TrueNAS, another running Proxmox, and several more old computers standing by waiting for a purpose. After a while I realized I was thinking too conventionally.

During this time, Apple released iPadOS 18 preview and a list of hardware they intend to support. Absent from that list is my 6th generation iPad. I bought it after disappointing experiences with a Windows 8 tablet and an Amazon Fire tablet. The tablet ecosystem is built around Apple’s iPad, and I’ve found products that undercut an iPad on price lack the hardware for smooth user experiences. For tablet centric usage scenarios, it was much more pleasant to use an iPad over the Samsung or Amazon Fire. On the flip side, I frequently felt limited by a tablet’s intentionally restricted capabilities. One example: I enjoy reading digital documents on an iPad, including documentation for software development tools. But when I get to a hands-on section, I have to switch hardware because an iPad is very deliberately not a general purpose computer and I can’t develop software on it.

With the knowledge that the clock is ticking on my 6th generation iPad, I started browsing for a replacement. My key priority is a USB type-C connector because I don’t want to deal with Apple Lightning cables anymore. Which meant the 10th generation iPad available for around $350. As I shopped around to see if I can get one for less than $350, it occurred to me that I should consider a Windows tablet/laptop convertible device. I had dismissed them for a long time because of first-hand experience with underpowered hardware and I wasn’t willing to pay the premium for high-end convertibles. But now I have a resource for heavily-discounted Dells business machines! I am willing to give Windows tablets another try when I can buy a powerful off-lease tablet/laptop convertible for new iPad money.

Roger Cheng

Dell XPS 8950 Components Replaced Under Warranty

My six-month-old Dell XPS 8950 has been exhibiting intermittent bug checks. (Blue screens of death.) Since it was still under warranty, I wanted Dell to fix it. The tech support department tried their best to fix it in software, but they eventually decided hardware component replacement will be required to get this system back up and running reliably.

The premium I paid for XPS included on-site service visits as a perk. Dell dispatched a technician (an employee of WorldWide Tech Services) to my home with a job order to replace SSD and power supply. This made sense: a bad SSD would corrupt system files and cause the kind of seemingly random and unpredictable errors I see. If the power supply had gone bad, intermittent power glitches can do the same. As far as system components go, they are relatively inexpensive and easy to replace, so it made sense for Dell to try that first.

Unfortunately, this repair job went awry. When the technician powered my system back up, there was no video from the RTX 3080 GPU. Intel’s integrated video worked if the GPU was removed so the rest of the system seemed fine. A follow-up visit had to be scheduled for another technician to arrive with a replacement RTX 3080 GPU to get things back up and running. I hope the first technician didn’t get in too much trouble for this problem as RTX 3080 cards are not cheap.

The evening after the system was back up, another bug check occurred. Two more occurred within the 24 hours that followed. I reported this back to Dell and they asked if I would be willing to send the system to a repair depot. I didn’t care how it was done, I just wanted my system fixed, so I agreed. They sent me a shipping box with packing material and a shipping label. I guess they didn’t expect people to hang on to the original box! (I did.)

Looking up the shipping label address, I found a match for CSAT Solutions. Apparently contracted by Dell to perform such repairs. These people worked fast! According to FedEx tracking information, it was delivered to CSAT at 11AM and by 4PM the box was back in FedEx possession for the return trip. I had set up the machine to run Folding@Home and I included instructions to reproduce the problem, but it’s clear they ain’t got time for that nonsense.

An invoice in the box indicated they replaced CPU and RAM. Two more components that, if faulty, can cause random bug checks. They are significantly more expensive than a SSD or power supply so I understand why they weren’t first to be replaced. (A RTX 3080 cost more, but wasn’t part of the plan.)

I reinstall Windows 11 again and fired up Folding@Home. This time there were no bug checks running for seven days nonstop. Hooray! I’m curious whether it was CPU or RAM at fault (or both?) but at this point I have no way to know.

Due to component replacements, I almost have a different computer. Of its original parts, the metal enclosure and main logic board are all that remained. Dell has fixed the computer under warranty with no financial cost to me but significant time cost. If I value my time at, say, $50 an hour, I would have been better off just buying a new computer. As for Dell, whatever profit they had made on this sale has been completely erased and became a net loss. I’m glad this problem was fixed under warranty, but both sides prefer to avoid doing it at all. I hope this gives them a financial incentive to improve system reliability!

Despite the headaches of this particular episode, the fact it was repaired under warranty made me quite willing to buy more refurbished Dell computers.

Roger Cheng

Notes On Diagnostics From Dell Support

My Dell XPS 8950 has started exhibited unpredictable bug checks. (Blue Screen of Death) I poked around Dell’s SupportAssist software and found a lot of promising troubleshooting tools, but none of them fixed it. Out of ideas on software fixes, and unwilling to void the warranty by modifying hardware, I used SupportAssist text chat feature to open an official trouble ticket with Dell technical support. They eventually fixed the issue, but it took a few weeks to get there.

As expected, they wanted to try the easy things first. This meant repeating many SupportAssist tools which I already knew would be doomed to fail. And Windows tools (like restore points) that did no better. Since hardware diagnostics tests passed, their suspicion moved to operating system corruption. This involved trying a lot of procedures I already knew about, and have already run, but they want to do it again. There were a few bits of novelty:

Throughout this arduous process,I was instructed to reinstall Windows three separate times in three different ways: first with SupportAssist’s OS reinstall option, then Windows’ built in recovery option, finally a clean install via an USB drive created with Microsoft’s Media Creation Tool. This is on top of the re-installation I had already performed before contacting Dell support. With all this practice, I got really good at Windows setup!

Each time I reinstalled Windows, I had to reinstall SupportAssist. Clicking on text chat created a new chat session. Which meant I was sent to someone expecting to open a new ticket and I’d have to spend time to get them straightened out with my existing ticket number.

With each bug check, I get a crash memory dump to prove their latest idea hadn’t resolved my issue. Sadly Dell’s support ticket web interface allowed only a maximum of five attachments. I quickly reached my limit and additional memory dumps had to submitted by sharing files via my Microsoft OneDrive and Google Drive accounts and sending a link via text chat. This was… sub-optimal.

Weeks later, I’ve exhausted all their scripted solutions and finally granted an escalation to senior support technicians. They reviewed my ticket and came to the conclusion I hoped they would: some hardware components would need to be replaced.

Roger Cheng

Notes on Dell SupportAssist

I have a thorny issue with my XPS 8950. The symptom is an intermittent bug check (a.k.a. blue screen of death) that is not readily reproducible and, even when it occurs, the error code varies wildly in type and in location. My previous trouble-free Dell computers have allowed me to ignore Dell’s tech support portal. Now I have a troubled PC and have to learn what’s in Dell’s SupportAssist software.

Dell SupportAssist is primarily a native Windows application that is pre-installed on every Dell PC. If it is lost, SupportAssist can be downloaded from Dell’s website. (I had to do this several times after performing operating system reinstall as a diagnostic procedure.) It has several roles to play in regular maintenance:

  • Look for common configuration problems and tries to fix them.
  • Download drivers and other system files, though mostly supplanted by Windows Update. I even got BIOS update 1.16.0 from Windows Update before it showed up as an option in SupportAssist.
  • Clean up unused files to free up disk space.

SupportAssist also included troubleshooting tools including:

  • Examine Windows system events. SupportAssist recognized that I had been experiencing bug checks, and even offered a “Fix Now” option. It’s not obvious what that did, but it didn’t help.
  • Perform a suite of hardware tests. CPU tests, memory tests, disk tests. I was amused it even spun up each of the fans.

Regarding the hardware tests: there’s also a separate piece of software that can run independent of Windows. Its title bar calls itself “SupportAssust | On-board Diagnostics” and it lives on a separate disk partition. To launch it, we have to trigger the BIOS boot select menu and select “Diagnostics”. My computer passed all of these tests as well, including running everything under “Advanced Test” with “Thorough mode” selected.

This diagnostics partition was deleted when following directions from Dell tech support to perform a completely clean install. I was worried about that — it seemed useful! — but I later learned SupportAssist Windows application can re-partition the hard drive and reinstall that Diagnostics partition.

There is one worrisome aspect of SupportAssist. When this native Windows application is installed on a system, the Dell web site running in a browser seems to be able to query hardware configuration in order to offer the appropriate documentation and driver downloads. How are those components communicating? I’m worried about that channel being a potential venue for security exploits.

There are many other features of SupportAssist I didn’t investigate because they didn’t seem helpful to me. Like tools to migrate data from one PC to another, and naturally an upsell for extended warranty coverage.

I ran every SupportAssist maintenance task and diagnostic test I could find, none helped. As a last resort I activated its operating system reinstall procedure, and that didn’t help either. I’m out of ideas for software fixes. If this were one of my home-built desktop PCs, I would start swapping out hardware to see if I can isolate it to a particular component. However, this computer is still under warranty so I don’t want to do anything that would void said warranty. If hardware replacements are to be done, it will have to be done by Dell people on Dell dime under warranty. To get that process started, I have to contact Dell technical support. I could call them over the phone, but that doesn’t seem like the best approach for an intermittent error that takes a day to reproduce. Fortunately SupportAssist includes a text chat client, and that seems more practical for my situation.

Roger Cheng

Dell XPS 8950 Bug Check Codes List

My Dell XPS 8950 I bought primarily for SteamVR started exhibiting bug checks at around six months old. It was eventually fixed under Dell’s one-year warranty, but the journey started with an attempt to diagnose it myself. Stressing it with Folding@Home would crash it once roughly every 12-24 hours.

When Windows halts with a bug check, a memory dump file is written to disk for debug purposes. It takes significant expertise to dig through a memory dump file to pinpoint a root cause. However, it’s pretty easy to get a general idea of what we are dealing with. We can install Windows debugger (WinDbg) and use its built-in automated analyzer to extract a top-level error code we can then look up online. Over the course of two weeks I ran Folding@Home to build a collection of memory dump files, hoping to find commonalities that might point at a source.

The best case scenario is to have the same bug check code on every dump, occurring in the same operating system component. What I got instead is a list of thirteen codes (appended at the bottom of this post), some more often than others. And even worse, they didn’t all happen at the same place in the system but was spread all around. The only vague commonality between them is an invalid memory operation. Sadly, “invalid memory operation” is too broad of a category to tie to a root cause. I became quite discouraged looking over those memory dumps.

I know Dell tech support has a database of bug check codes and a list of diagnostic steps to address each of them. First level support technicians are trained to tell the customer to try each item in turn. Figure a half dozen things they want me to try (probably starting with “please turn off and back on again”…) for each of 13 possible codes means I will have to trudge through a lot of those procedures.

Eventually my support ticket will establish a widespread pattern that escalate my case to more senior support staff who will look at the problem more holistically, but I have to earn it with persistence! I will be spending a lot of time with Dell tech support, starting with their preinstalled troubleshooting tool called SupportAssist.

Bug check codes encountered, with URL of the Microsoft reference page and the first sentence of their explanation pasted in after the code.

Roger Cheng

Dell XPS 8950 Stress Test with Folding@Home

I had another lengthy saga running In parallel with my lengthy Canon Pixma MX340 teardown. The Dell XPS 8950 I bought primarily for SteamVR with my Valve Index began exhibiting bug checks on an irregular basis. This is not good. I paid a premium over similar-spec computers on the expectation that a XPS would be more reliable and, failing that, Dell is more likely to fix things that go wrong. Well, the first part turned out to be wrong. Thankfully the second part was eventually tested to be true, but it took some work to get there.

The first thing I needed was a better way to reproduce the issue. I want to collect many bug check memory dumps to compare them against each other, and I needed a way to verify the problem has been resolved or not. Since I bought this computer mainly for SteamVR, the bug check usually happens while I’m in the middle of a VR session. It spoiled a few Beat Saber songs and abruptly ended firefights with Combine soldiers in Half Life: Alyx, but not every VR session triggered the problem and I wasn’t going to just stay in VR until it occurred.

I found hardware tests in Dell’s SupportAssist tool (more on SupportAssist in a future post) and ran those. My computer passed the tests with no errors. I looked for a way to run these tests in a loop but didn’t find a way to do so.

I tried just leaving the computer on and running, but not doing anything in particular. After a week, I got two bug checks. This is better than unpredictable crashes in VR sessions, but waiting 3-4 days between reproducing a failure is still not great.

I increased system workload by installing and running Folding@Home. It kept the GPU busy but CPU utilization would drop off after a few minutes. I eventually figured out Windows 11 detected a long-running compute process and decided to restrict Folding@Home to the four power-efficient E-Cores on my i7-12700 CPU. Gah, foiled! I worked around this by disabling the E-Cores in system BIOS. (Where they were called Atom Cores.) With E-Cores out of the picture, CPU utilization stays at 100% with all eight hyper-threaded P-cores running at full blast.

I would rather have a procedure to consistently and immediately reproduce the crash but I never found one. Running Folding@Home the bug check would usually occur within 12-24 hours and this was the best I’ve got. Over the course of about two weeks, Folding@Home helped me generate a decently sized collection of bug check crash memory dumps to examine.

Roger Cheng

Configuring Laptop for Proxmox VE

I’m migrating my light-duty server duties from my Dell Latitude E6230 to my Dell Inspiron 7577. When I started playing with KVM hypervisor on the E6230, I installed Ubuntu Desktop instead of server for two reasons: I didn’t know how to deal with the laptop screen, and I didn’t know how to work with KVM via the command line. But the experience allowed me to learn things I will incorporate into my 7577 configuration.

Dealing with the Screen

By default, Proxmox VE would leave a simple text prompt on screen, which is fine because most server hardware don’t even have screens attached. On a laptop, keeping the screen on wastes power and probably cause long-term damage as well. I found an answer on Proxmox forums:

  • Edit /etc/default/grub to add “consoleblank=30” (30 is timeout in seconds) to GRUB_CMDLINE_LINUX if an entry already existed. If not, add a single line GRUB_CMDLINE_LINUX="consoleblank=30"
  • Run update-grub to apply this configuration.
  • Reboot

Another default behavior: when closing the laptop lid, the laptop goes to sleep. I don’t want this behavior when I’m using it as mini-server. I was surprised to learn the technique I found for Ubuntu Desktop would also work for server edition as well: edit /etc/systemd/logind.conf and change HandleLidSwitch to ignore.

Making the two above changes turn off my laptop screen after the set number of seconds of inactivity, and leaves the computer running when the lid is closed.

Dealing with KVM

KVM is a big piece of software with lots of knobs. I was intimidated by the thought of learning all command line options and switches on my own. So, for my earlier experiment, I ran Virtual Machine Manager on Ubuntu Desktop edition to keep my settings straight. I’ve learned bits and pieces of interacting with KVM via its virsh command line tool, but I have yet to get comfortable enough with it to use command line as the default interface.

Fortunately, many others felt similarly and there are other ways to work with a KVM hypervisor. My personal data storage solution TrueNAS has moved from a FreeBSD-based system (now named TrueNAS CORE) to a Linux-based system (a parallel sibling product called TrueNAS SCALE). TrueNAS SCALE included virtual machine capability with KVM hypervisor which looked pretty good. After a quick evaluation session, I decided I preferred working with KVM using Proxmox VE, a whole operating system built on top of Debian/Ubuntu dedicated to the job. Hosting virtual machines with the KVM hypervisor and tools to monitor and manage those virtual machines. Instead of Virtual Machine Manager’s UI running on Ubuntu Desktop, both TrueNAS SCALE and Proxmox VE expose their UI as a browser-based interface accessible over the network.

I liked the idea of doing everything on a single server running TrueNAS SCALE, and may eventually move in that direction. But there is something to be said of keeping two isolated machines. I need my TrueNAS SCALE machine to be absolutely reliable, an appliance I can leave running its job of data storage. It can be argued it’s a good idea to use a different machine for more experimental things like ESPHome and Home Assistant Operating System. Besides, unlike normal people, I have plenty of PC hardware sitting around. Put some of them to work!

Roger Cheng

Dell Inspiron 7577 Laptop as Light Duty Server

I’m setting aside my old Dell Latitude E6230 laptop due to its multiple hardware failures. At the moment I am using it to play with virtualization server software. Virtualization hosts usually run on rack-mounted server hardware in a datacenter somewhere. But an old laptop works well for light-duty exploration at home by curious hobbyists: they sip power for small electric bill impact, they’re compact so we can stash them in a corner somewhere, and they come with a battery for surviving power failures.

I bought my Dell Inspiron 7577 15″ laptop five years ago, because at the time that was the only reasonable way to get my hands on a NVIDIA GPU. The market situation have improved since then, so I now have a better GPU on my gaming desktop. I’ve also learned I haven’t needed mobile gaming power enough to justify carrying a heavy laptop around, so I got a lighter laptop.

RAM turned out to be a big constraint on what I could explore on the E6230. Which had a meager 4GB RAM and I couldn’t justify spending money to buy old outdated DDR2 memory. Now I look forward to having 16GB of elbow room on the 7577.

While none of my virtualization experiments demanded much processing power, more is always better. This move will upgrade from a 3rd-gen Core i5 3320M processor to a 7th-gen Core i5 7300HQ. Getting four hardware cores instead of two hyperthreaded cores should be a good boost, in addition to all the other improvements made over four generations of Intel engineering.

For data storage, I’ve upgraded the 7577 from its factory M.2 NVMe SSD from a 256GB unit to a 1TB unit, and the 7577 chassis has an open 2.5″ SATA slot for even more storage if I need it. The E6230 had only a single 2.5″ SATA slot. Neither of these machines had an optical drive, but if they did, that can be converted to another 2.5″ SATA slot with adapters made for the purpose.

Both of these laptops have a wired gigabit Ethernet port, sadly a fast-disappearing luxury in laptops. It eliminates all the unreliable hassle of wireless networking, but an Ethernet jack is a huge and bulky component in an industry aiming for ever thinner and lighter designs. [UPDATE: The 7577’s Ethernet port would prove to be a source of headaches.]

And finally, the Inspiron 7577 has a hardware-level feature to improve battery longevity: I could configure its BIOS to stop battery charging at 80% full. This should be less stressful on the battery than being kept at 100% full all the time, which is what the E6230 would do and I could not configure it otherwise. I believe this deviation from laptop usage pattern contributed to battery demise and E6230 retirement, so I hope the 80% state of charge limit will keep the 7577 battery alive for longer.

When I started playing with KVM hypervisor on the E6230, I installed Ubuntu Desktop instead of server for two reasons: I didn’t know how to deal with the laptop screen, and I didn’t know how to work with KVM via the command line. Now this 7577 configuration will incorporate what I’ve learned since then.

Roger Cheng

Dell Latitude E6230 Getting Benched

I’ve got one set of dead batteries upgraded and tested and now attention turns to a different set of expired batteries. I bought this refurbished Dell Latitude E6230 several years ago intending to take apart and use as a robot brain. I changed my mind when it turned out to be a pretty nifty little laptop to take on the go, much smaller and lighter than my Dell Inspiron 7577. With lower specs than the 7577, it also had longer battery run time and its performance didn’t throttle as much while on battery. It has helped me field-program many microcontrollers and performed other mobile computing duties admirably.

I retired it from laptop duty when I got an Apple Silicon MacBook Air, but I brought it back out to serve as my introduction to running virtual machines under KVM hypervisor. Retired laptops work well as low-power machines for exploratory server duty. Running things like Home Assistant haven’t required much in the way of raw processing power, it was more important for a machine to run reliably around the clock while stashed unobtrusively in a corner somewhere. Laptops are built to be compact, energy-efficient, and already have a built-in battery backup. Though the battery usage pattern will be different from normal laptop use, which caused problems long term.

Before that happened though, this Latitude E6230 developed a problem starting up when warm. If I select “restart” it’ll reboot just fine, but if I select “shut down” and press the power button immediately to turn it back on, it’ll give me an error light pattern instead of starting up: The power LED is off, the hard drive LED is on, and the battery LED blinks. Given the blinking battery LED I thought it indicated a problem with the battery, but if I pull out the battery to run strictly on AC, I still see the same lights. The workaround is to leave the machine alone for 20-30 minutes to cool down, after which it is happy to start up either with or without battery.

But if the blinking battery LED doesn’t mean a problem with the battery, what did it mean? I looked for the Dell troubleshooting procedure that would explain this particular pattern. I didn’t get very far and, once I found the workaround, I didn’t invest any more time looking. Acting as a mini-server meant it was running most of the time and rarely powered off. And if it does power off for any reason, this mini-server isn’t running anything critical so waiting 20 minutes isn’t a huge deal. I decided to just live with this annoyance for a long time, until the second problem cropped up recently:

Now when the machine is running, the battery LED blinks yellow. This time it does indicate a problem with the battery. The BIOS screen says “Battery needs to be replaced”. The Ubuntu desktop gives me a red battery icon with an exclamation mark. And if I unplug the machine, there’s zero battery runtime: the machine powers off immediately. (Which has to be followed by that 20 minute wait for it to cool down before I can start it up again.)

I knew keeping lithium-ion batteries at 100% full charge is bad for their longevity, so this was somewhat expected. I would have preferred the ability to limit state of charge at 80% or so. Newer Dell laptops like my 7577 have such an option in BIOS but this older E6230 did not. Given its weird warm startup issue and dead battery, low-power mini-server duty will now migrate to my Inspiron 7577.

Roger Cheng

PC Power Supply Fan Replacement (CWT GPS650S)

While learning electronics by reverse-engineering board schematics, one of my computers started making an intermittent growling noise. I suspect a failing fan bearing. Probably not a big deal, as mechanical things wear, and failure is inevitable. I traced the sound to a Channel Well Technology GPS650S power supply’s internal fan. This computer has a 9th gen Core i7 CPU, which launched in 2019 so this power supply has been running for roughly four years. This is on the short end of PC cooling fan lifespan, but hopefully just bad luck of being on the short end of the bell curve.

Looking on the bright side, I know how to replace a failing fan. So given a choice I prefer this failure mode versus blowing a non-user replaceable fuse or burning up.

Getting past a few “no user serviceable parts inside” and “warranty void if removed” stickers opened up the enclosure to access the 120mm 12VDC fan.

Something’s definitely wrong with the fan, as the label isn’t supposed to get puffy and shiny in the middle like that. This is consistent with friction heat generated by a failing bearing.

Fortunately, the fan seems to be plugged in to the power supply control board with a commodity JST-XH 2-position connector.

Sitting on my shelf are multiple 120mm 12VDC cooling fans that can serve as suitable replacement. One of them even has a JST-XH connector already installed. Judging by the sheet of airflow control plastic on this fan, it was salvaged from another power supply. Probably the the one that blew an inaccessible fuse.

Unfortunately it was not that easy, but that was my own fault. I connected it up to my bench power supply dialed up to 12V DC for a test. It spun up nicely and when I reached over to disconnect power I knocked the fan grill into the fan. The fan, spinning at full speed, dealt with the sudden stop by snapping off a blade. Rendering the fan useless. D’oh!

But I had other fans to spare, including one with an Antec sticker that probably meant it came from the power supply that went up in smoke. It should work just as well, merely a bit less convenient for me because I had to cut off its existing connector and crimp my own JST-XH compatible connector. This time I was more careful with the spin-up test and did not break a blade.

The power supply is now back in action, running quietly with a replacement salvaged fan. And now I have two broken fans on hand: one with a bad bearing and another with a broken blade.

Roger Cheng

Potential Small PC Explorations

I had fun playing with the GMKtec NucBox3, an interesting and capable little PC more affordable than Intel’s NUC product line, naturally with some expected tradeoffs for its lower cost. I learned about these little PCs from a Newegg advertisement and, between the time I ordered one and its arrival, I had a failed USB external drive that I transplanted into a small form factor Dell PC. Computers in these two projects represent a spectrum that I should keep in mind for future project possibilities. Which one I buy would depend on a project’s requirements.

Intel NUC

A genuine Intel NUC would be more expensive than any of the other options below, but sometimes it’s worth spending that money. For example, if I’m building a solution that needs to be reliable, I will pay more for a brand name. Or if I want to design something that can be repeated by others, it’s easier for someone to buy an identical Intel NUC than to find, say, a GMKtec. For this reason: If my Sawppy rover ever changes over to an x86-64 PC ROS brain, the official recommended hardware will be an Intel NUC. (Supplemented with suggestions on what to look for in lower-cost alternatives like the NucBox3.)

Just Below $90

But when we’re feeling adventurous and not particularly motivated to pay for quality or consistency, we can go bargain hunting. Searching for various options, I observed a price floor somewhere in the $80-$90 range. I see an interesting hint of economic factors at play preventing things from much lower than $90, but I don’t know what they might be. (As a point of comparison, Raspberry Pi 4 8GB MSRP is $75.)

Lowest Bidder du Jour

Amazon categorized these products under: “Electronics” > “Computers & Accessories” > “Computers & Tablets” > “Desktops” > “Minis”. Sorting them by price today, I see several options right around $89, roughly 40% discount from the price of a NucBox3. To get to that price point we have to give up many things. For example, this item (*) made some notable tradeoffs:

  • Memory is half the size (4GB vs. 8GB), uses older technology (DDR3 vs. DDR4), and is soldered in never to be upgraded.
  • Storage is half the size (64GB vs 128GB), uses much slower technology (eMMC vs. SATA) and is also permanently soldered. However, it does have a 2.5″ SATA bay, which the NucBox3 does not.
  • CPU is three years older and from a different product generation (Celeron J3455 vs. J4125) and it doesn’t meet hardware requirements for Windows 11.

On the upside, it still meets all my hard requirements for robot brain: 64-bit CPU running x86-64/amd64 instruction set, gigabit Ethernet port, small, lightweight, and might run on battery power. Depending on future project requirements, I may choose these tradeoffs in favor of a <$90 bargain.

Buying Refurbished

Looking at inexpensive PCs on Amazon, I saw a lot of refurbished units. Clicking around a few listings, I learned Amazon had set up an entire department. “Amazon Renewed” is dedicated to refurbished products of all kinds, not just computers. I should definitely keep this in mind as an option. Given my personal experience, I’d restrict my search to refurbished Dell products from their corporate line. Which would still leave me with very many options. Check out these guys, each offered at a few bucks under $90:

  • Optiplex 3040 Micro Desktop (*) are bigger than an Intel NUC, but tiny compared to anything else. Skimming Dell’s manual, I see a 2.5″ SATA bay inside. I also see what looks like a M.2 slot on a picture of its mainboard, but M.2 isn’t called out in the manual as a storage option. I see a gigabit Ethernet port and it accepts power from a DC barrel jack, so there’s a possibility it can be persuaded to run on battery power.
  • Optiplex 790 USFF Desktop (*) are significantly larger. Packing an optical drive on top of a 2.5″ drive bay and AC power supply. No robot battery power for this machine, but dual 2.5″ drives are possible via an optical drive caddy. This could work for TrueNAS replication target if my storage drive is a high capacity 2.5″ laptop hard drive.
  • Optiplex 3020 SFF Slim Desktop (*) is a successor to the Optiplex 960 I repurposed to a TrueNAS replication target, with at least one 3.5″ drive bay and one optical drive bay. This would be my default choice if I need to build another replication target machine.

What if I want a parallel port for LinuxCNC? Sadly, that’s an uncommon enough request I can’t filter on Amazon. But when it comes to refurbished small Dell PCs, Amazon Renewed is not the only game in town. There are plenty of other vendors like PC Liquidations, who offers filtering by parallel port. Resulting in a list of refurbished Dell Optiplex with parallel port starting at, you guessed it, a few dollars under $90. All good options if I want to dedicate a cheap PC to a task, which usually also requires me to set up automatic software updates.

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

Good First Impressions of GMKtec NucBox3

It was fun to poke around internal hardware of a tiny PC I wanted to investigate for use as a robot brain. This GMKtec NucBox3 I ordered off Amazon (*) is a more affordable variation on the Intel NUC formula, and its price (significantly lower than Intel’s own NUC) makes me more willing to experiment with it.

Decent PC for Windows 11 Home

But before I take any risk with nonstandard usage, I should verify it worked as advertised. The 128GB SATA SSD came installed with Windows 11 Home edition build 21H2. Upon signing in with my Microsoft account, it started the update process to build 22H2. I assumed the machine came with a license of Windows either embedded in the hardware or otherwise registered. Windows 11 control panel “Activation state” says “Windows is activated with a digital license linked to your Microsoft account” which I found to be ambiguous. I shrugged because I plan to use it as ROS brain and, if so, I’m likely to run Ubuntu instead of Windows. And if I wipe the SATA drive with a fresh installation of Windows 11, it sounds like I can log in with my Microsoft account and retrieve its license.

The more informative aspect of Windows sign-in and registration is letting me get a feel of the machine in its default configuration. All hardware drivers are in place with no question marks in device manager. Normal user interface tasks were responsive and never frustrating, which is better than certain other budget Windows computers I’ve tried. A NucBox3 is a perfectly competent little Windows box for light duty computer use.

One oddity I found with the NucBox3 was the lack of a power-up screen letting me change boot behavior with a keypress. When a PC first powers up, there’s typically a prompt telling me to press F12 to enter a menu to select a boot device, or DEL to enter system setup, etc. Not on a NucBox3, though: we always boot directly into Windows. The only way I found to enter hardware menu was from within Windows: under “Settings”/”System”/”Recovery” we can choose “Advanced startup” to boot into a special Windows menu, where I can select “Advanced Options” and choose “UEFI Firmware Settings”. This is expected to be an infrequent activity most users would never do, so I guess it’s OK for the process to be a convoluted.

UEFI Menu

Once I got into UEFI menu for NucBox3 I was surprised by how many options are listed. Far more than any branded (Dell, etc) computer I’ve seen and even more than hobbyist-focused motherboards.

Some of these options like “Debug Configuration” almost feel like they weren’t supposed to ship in a final product. My hypothesis is that I’m looking at the default full menu of options for a manufacturer using this AMI (American Megatrends, Inc) UEFI firmware. Maybe the manufacturer was expected to trim it down as appropriate for their product, and maybe nobody bothered to do that.

Under the “Chipset” menu we have device configuration for many peripherals absent from this device. They’re marked [Disabled] but the menu option didn’t even need to be here. The final line was also the most surprising: a selection for resistors on I2C buses. On one hand, I’ve never seen a PC’s I2C hardware exposed in any user-visible form before. On the other hand, if I can figure out where SDA/SCL lines are on this motherboard, maybe I can really have some fun. Why bother with a Raspberry Pi or even an ESP32 to bridge I2C hardware if I can attach them directly to this PC?

Ubuntu Server

But all those shiny lights in UEFI menus were just a distraction. What I really want right now is to control boot sequence so I can boot from a USB flash drive to install Ubuntu Server 22.04 LTS. I found I could do it from the “Boot” section of UEFI menu. Ubuntu Server was installed, it worked, and that was no surprise. A computer competent at a full Windows 11 GUI rarely has a problem with text-based network-centric Ubuntu Server, and indeed I had no problems here. For a ROS brain I would want gigabit networking, all four CPU cores, RAM, storage, and USB peripherals. They are all present and accounted for, even sleep mode if I want to put a robot to sleep.

Variable Input Voltage

The next experiment was to see if this computer is tolerant of variable DC supply voltage. On paper it requires 12V DC and the supplied AC adapter was measured at 12.27V DC. I could buy a boost/buck converter that takes a range of input voltages and output a steady 12V (*) but it would be more efficient to run without such conversion if I could get away with it. Since the NucBox3 used a standard 5.5mm OD barrel jack for DC power input, it was easy to wire it up to my bench power supply. I found it was willing to boot up and run from 10VDC to 12.6VDC, the operating voltage range of 3S LiPo battery packs.

Good ROS Brain Candidate

This little computer successfully ran Ubuntu Server on (simulated) battery power. It handily outperforms the Dell 11 3180 I previously bought as ROS brain candidate and is much more compact for easy integration on robot chassis. Bottom line, I have a winner on my hands here!

I’m glad that Newegg advertisement made me aware of an entire ecosystem of inexpensive small PCs. I need to keep this product category in mind as candidates for potential future projects. I have many options to consider, depending on a project’s needs.

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

Looking Inside GMKtec NucBox3

I thought the GMKtec NucBox3 looked interesting (at least on paper) as candidate ROS brain, so I ordered one (*) for a closer look despite some skepticism. All pictures on that Amazon listing look perfect, I suspected they were all 3D computer renders instead of photos of an actual product. There’s a chance the actual product looked very different from the listing.

The good news: the product is real and for the most part, as depicted in the listing. I find good fit and finish on its plastic enclosure. There is one downside: fingerprints show up very clearly. I had to wipe down the case pretty aggressively for these pictures and I still see greasy smudges. Well, at least you know these aren’t renders! One instance where oily fingerprint smudges are a feature, not a bug.

I see two brass heat-set inserts on the bottom of the case which will be useful for mounting this little box somewhere. They look very small but this is a small lightweight box so it would probably suffice.

Here we also see where actual product differed from product listing rendering. The company website page for NucBox3 showed an access panel to upgrade memory or storage.

But there’s no such access panel on the real thing, and it’s not clear how to get inside without one. Documents in the box consisted of a minimal warranty card in the box and no instruction manual. No matter, the lack of a convenient access panel or a manual shall not deter me from getting inside for a look.

Hiding fasteners under glued-on rubber feet is a common and effective technique. These four fasteners are not symmetrical so, even though the box is a square, we need to remember correct orientation to reinstall.

Without a convenient access door for upgrades, I wasn’t sure what else would differ from listing picture. I was afraid memory and storage would be soldered-in parts, but I was relieved to find they were standard DDR4 RAM and M.2 2280 SSD as advertised. They’re just a tiny bit harder to access without the panel.

Judging by its M.2 keys, we have the option to upgrade this factory-installed SATA M.2 SSD to a higher-performing NVMe M.2 SSD if needed.

What appears to be empty threaded holes (marked with circles) are actually used to secure the CPU heatsink from the other side. (There’s a fourth one under RAM module and not visible in this image.) Four fasteners (marked with squares) secure the motherboard and must be removed to proceed.

The headphone jack protrudes into the enclosure, so we must tilt the mainboard from the opposite side for removal. But we have to be careful because we are limited by length of WiFi antenna wires.

A block of foam keeps WiFi antenna connectors in place, peeling it back allowed the connectors to be released. The antennae themselves appear to be thin sheets glued to the top of the case, similar to what I’ve salvaged from laptops. How securely were they held? I don’t know. I didn’t try to peel them off.

Freed of WiFi wires, I could flip the mainboard over to see a big heatsink surrounded by connectors. As chock-full of connectors as this product already is, I was surprised to see that there are still several provisions for even more connectors on the circuit board. I’m also very fascinated by connectors used here for USB3, HDMI, and DisplayPort. I usually see them oriented flat against the circuit board as typical of laptop mainboards, but without design pressure to be thin, these connectors are standing upright. This is a tradeoff to fit more connectors on the edge of a circuit board, but each connector must go deeper to obtain the necessary mechanical strength to withstand use.

Looking in from the side, the heatsink appears to have a flat bottom. This is good news if I want to mount a different heatsink on this board, possibly with a fan. The flat bottom means I don’t have to worry about sticking out to make thermal contact with other chips or have to cut a hole to clear protrusions. If I want to mount to the same holes, I will have to drill four holes which unfortunately are irregularly spaced but not an insurmountable challenge. All that said, I’m more likely to just point a fan at this heatsink if heat proves to be a problem.

Using this computer as robot brain also means running it on battery power. Nominal power requirements are listed as 12V up to 3A. My voltmeter measured the factory power adapter output at 12.27V. But what can this thing tolerate? I found this chip directly behind the DC power barrel jack, but a search for DC3905 WK1MEG (or WX1MEG) didn’t turn up anything definitive. Texas Instruments has a LP3905 and Analog inherited Linear Technology’s LT3905. Both chips are designed for DC power handling, but neither footprint matches this chip. This might not even be the power management chip, I’m only guessing based on its proximity to the DC barrel jack.

As far as I know, the highest voltage requirement on this PC are USB ports at 5V. On the assumption that nothing on this machine actually needs 12V, then all power conversion are buck converters to lower voltage levels. If true, then this little box should be OK running directly on 3S LiPo power (Three lithium-polymer battery cells in series) which would range from 12.6V fully charged to 11.1V nominal to 10V low power cutoff. I’ll use the power brick that came in the box to verify everything works before testing my battery power hypothesis.

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

SATA Optical to 2.5″ Drive Adapter

I dusted off an old Dell Optiplex 960 for use as my TrueNAS replication backup target. The compact chassis had a place for my backup storage 8TB 3.5″ HDD extracted from a failed USB enclosure, which is good. But I also need a separate drive for Ubuntu operating system, and that’s where I ran into problems. There was an empty 3.5″ bay and a SATA data socket available on the motherboard, but the metal mounting bracket was missing, and power supply had no more SATA power plugs.

As an alternative plan, I thought I would repurpose the optical drive’s location. Not just its SATA data and power plugs, but I could also repurpose physical mounting bracket with an optical drive shaped caddy for a 2.5″ SATA drive. (*) It wasn’t a perfect fit but that was my own fault for ordering the wrong size.

Examining the caddy after I opened its package, I saw this oddly bent piece of sheet metal. Comparing against the DVD drive, I don’t think it’s supposed to bend like that. I can’t tell if it was damaged at the factory or during shipping, either way metal was thin and easy to bend back into place.

Also comparing against the DVD drive, I realized I bought the wrong size. It didn’t occur to me to check to see if there were multiple different sizes for laptop DVD drives. I bought a 9.5mm thick caddy (*) when I should have bought something thicker possibly this 12.7mm thick unit.(*) Oh well, I have this one in hand now and I’m going to try to make it work.

To install this caddy in an Optiplex 960 chassis, I need to reuse the sheet metal tray currently attached to the DVD drive.

One side fit without problems, but the other side didn’t fit due to mismatched height. This is my own fault.

There’s a mismatch in width as well, I’m not sure this was my fault. I understand the different form factors to be the same width so this part should have lined up. Oh well, at least it is easier to deal with a ~1mm too narrow adapter because one ~1mm too wide wouldn’t fit at all.

There were slots to take the DVD drive’s faceplate. This is for aesthetics so we don’t leave a gaping hole, the eject button wouldn’t work as it is no longer a DVD drive. Unfortunately, faceplate mounting slots didn’t match up, either. This might also be a function of the wrong height, but I’m skeptical. I ended up using the generic faceplate that came with the caddy.

Forcing everything to fit results in a caddy mounted crookedly.

Which resulted in a crooked facade.

Aesthetically speaking this is unfortunate, I should have bought a taller caddy (*) but functionally this unit works fine. The SSD is securely mounted in the caddy, which is now securely mounted to the chassis. And even more importantly, SATA power and data communication worked just fine, allowing me to install Ubuntu Server 22.04 LTS on an old small SSD inside the caddy. And about that old SSD… freeing it up for use turned out to be its own adventure.

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

Dusting Off Dell Optiplex 960 SFF PC

After two years of use, my USB3 external 8TB backup drive stopped responding as an external disk. I took apart its enclosure and extracted a standard 3.5″ hard disk drive which seems OK in perfunctory testing. In order to continue using it for TrueNAS replication backup, I’ll need another enclosure. I briefly contemplated getting an USB3 SATA enclosure that takes 3.5″ drives (*) but I decided to use an entire computer as its enclosure: I have an old Dell Optiplex 960 SFF (small form factor) PC collecting dust and it would be more useful as my TrueNAS replication backup machine.

Dell’s Optiplex line is aimed at corporate customers, which meant it incorporated many design priorities that weren’t worth my money to buy new. But those designs also tend to live well past their first lives, and I have bought refurbished corporate Dells before. I’ve found them to be sturdy well-engineered machines that, on the secondhand market, is worth a small premium over generic refurbished PCs.

There’s nothing garish with exterior appearance of an Optiplex, just the computer equivalent of professional office attire. This particular machine is designed to be a little space-efficient box. Office space costs money and some companies decide compactness is worth paying for. Building such a compact box required using parts with nonstandard form factors. For a hobbyist like me, not being able to replace components with generic standard parts is a downside. For the corporate IT department with a Dell service contract, the ease of diagnosis and servicing is well worth the tradeoff.

This box is just as happy sitting horizontally as vertically, with rubber feet to handle either orientation.

Before it collected dust on my shelf, this computer collected dust on another maker’s shelf. I asked for it sometime around the time I started playing with LinuxCNC. I saw this computer had a built-in parallel port, so I would not need an expansion card. (Or I can add a card for even more control pins.) The previous owner said “Sure, I’m not doing anything with it, take it if you will do cool things with it.” Unfortunately, my LinuxCNC investigation came to a halt due to pandemic lockdown and I lost access to that space. TrueNAS replication target may not be as cool as my original intention for this box, but at least it’s better than collection dust.

Even though the chassis is small, it has a lot of nice design features. The row of “1 2 3 4” across the front are diagnostics LEDs. They light up in various combinations during initial boot-up so, if the computer fails to boot corporate IT tech support can start diagnosing failure before even opening up the box.

Which is great, because opening up the box might be hindered by a big beefy lock keeping the side release lever from sliding.

And if we get past the lock and open the lid, we trip the chassis intrusion detection switch. I’ve seen provision for chassis intrusion detection in my hobbyist-grade motherboards, but I never bothered to add an actual intrusion switch to any of my machines. Or a lock, for that matter.

Once opened I find everything is designed to be worked on without requiring specific tools. This chassis accommodates two half-height expansion cards: One PCI and one PCI-Express. On my PCs, expansion endplates are held by small Philips-head screws. On this PC, endplates are retained by this mechanism.

A push on the blue button releases a clamp for access to these endplates.

Adjacent to those expansion slots is a black plastic cage for 3.5″ Hard drive.

Two blue metal clips release the cage to flip open, allowing access to the hard drive. This drive was intended to be the only storage device hosting operating system plus all data. I plan to install my extracted 8TB backup storage drive in this space, which needs to be a separate drive from the operating system drive, so I need to find another space for a system drive.

Most of the motherboard is visible after I flipped the HDD cage out of the way. I see three SATA sockets. One for the storage HDD, one for the DVD drive, and an empty one I can use for my system drive. Next to those slots is a stick of DDR2 RAM. (I’m quite certain Corsair-branded RAM is not original Dell equipment.) Before I do anything else with this computer, I will need to replace the CR2032 coin cell timekeeping battery.

A push on the blue-stickered sheet metal button released the DVD drive. Judging by scratches, this DVD drive has been removed and reinstalled many times.

Putting the DVD drive aside, I can see a spare 3.5″ drive bay underneath. This was expected because we could see a 3.5″ blank plate in the front of this machine, possibly originally designed for a floppy disk drive. The good news is that this bay is empty and available, the bad news is that a critical piece of hardware is missing: This chassis is designed to have a sheet metal tray for installing a 3.5″ drive, which is not here.

I can probably hack around the missing bracket with something 3D-printed or even just double-sided tape. But even if I could mount a small SSD in here, there are no spare SATA power connector available for it. This is a problem. I contemplated repurposing the DVD drive’s power and data cables for a SSD and found adapters cables for this purpose. (*) But under related items, I found a product I didn’t even know existed: an optical-to-hard drive adapter (*) that doesn’t just handle the power and data connectors, it is also a mechanical fit into the optical drive’s space!

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

Window Shopping: GMKtec NucBox3 Mini PC

A Newegg advertisement sent me down a rabbit hole of tiny little desktop PCs with full x86-64 processors. I knew about Intel’s NUC, but I hadn’t realized there was an entire product ecosystem of such small form factor machines built by other manufacturers. The one that originally caught my attention was distributed by several different companies under different names, I haven’t figured out who made it. But that exploration took me to GMKtec which is either their manufacturer, or a distributor with a sizable collection of similar products built by different manufacturers. The product that originally caught my attention is listed as their “NucBox5” (company website listing and Amazon link *) but I actually found their “NucBox3” (company website listing and Amazon link *) to be a more interesting candidate for my Sawppy Rover’s ROS brain. Both products have a Gigabit Ethernet wired networking port that I demand for resistance against RF interference, but beyond that, their respective designs differ wildly:

First the bad news: the NucBox 3 has an older CPU, the Celeron J4125 instead of the Celeron N5105. But comparing them side-by-side, it looks like I’d be giving up less than 10% of peak CPU performance. There is a huge (~50%) drop in GPU performance, but that doesn’t matter to Sawppy because most of the time its brain wouldn’t even have a screen attached.

A longer list of good stuff balances out the slower CPU:

  • RAM on the NucBox 3 is a commodity DDR4 laptop memory module. That can be easily upgraded if needed, unlike the soldered-in memory on the NucBox 5.
  • They both use M.2 SSDs for storage, but the NucBox 3 accommodates popular 2280 form factor instead of a less common 2245 size used by NucBox 5.
  • The SSD advantage was possible because NucBox 3 has a different shape: is wider and deeper than a NucBox 5, but not as tall. Designed for installation on a VESA 100×100 mount, it will be easier to bolt onto a rover chassis.
  • Officially, NucBox 3 is a fan-less passively cooled machine whereas the NucBox 5 has a tiny little cooling fan inside. (Which I expect to be loud, as tiny cooling fans tend to be.) Given that these are both 10W chips, I doubt NucBox 3 has a more effective cooling solution, I think it is more likely that the design just lets the chip heat up and throttle itself to stay within thermal limits. This would restrict its performance in stock form, but it also means it’ll be easy for me to hack up a quiet cooling solution if necessary.
  • NucBox 5 accepts power via USB-C, which is getting easier and easier to work with. I foresaw no problems integrating it with battery power onboard a Sawppy rover. But the NucBox 3 has a generic 5.5mm barrel jack for DC input power, and I think that’ll be even easier.

A NucBox3 costs roughly 80% of a NucBox5 for >90% of the performance, plus all of the designed tradeoff listed above are (I feel) advantages in favor of the NucBox3. I’m sold! I placed an order (*) and look forward to playing with it once it arrives.

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.