Seagate Backup+ Hub External Drive 8TB (SRD0PV1) Teardown

I’ve owned and taken apart several USB external hard drives to extract their standard form factor SATA hard drive within. Today another drive shall undergo an extraction process. This is a Seagate Backup Plus Hub (SRD0PV1) I had used to back up my TrueNAS disk array. I used a Raspberry Pi as TrueNAS replication host and this drive as storage. I paid a few extra bucks for the version with an integrated USB hub hoping to power my Raspberry Pi from one of the ports and simplify my wiring. Unfortunately, I learned that when the drive initially spins up, all power goes to the drive and these USB ports become momentarily disconnected. Shutting down the Pi sank my plan. I shrugged, chalked the few extra bucks to lesson learned and ignored its integrated USB ports. I powered my Pi conventionally and used the drive for TrueNAS replication back up storage. That daily backup setup worked for about two years before TrueNAS started reporting replication failures: “Device not found.” Where did it go? Looks like my Raspberry Pi would acknowledge the drive existed as a USB device but couldn’t use it as one.

Running Ubuntu’s dmesg command and querying for all the lines that have USB in it, I found a trail ending with an error message “Cannot enable. Maybe the USB cable is bad?” Following that advice, I tried several different cables but that didn’t make a difference, so it wasn’t the cable. I tried plugging the drive into my Windows machine with similar results: New USB device? Yes. New hard drive? No.

Thus it was time for another hard drive shucking session. Since my TrueNAS array is running well, the data within isn’t critical right now. But it’s a low-pressure opportunity to learn if my data backup would survive such an episode of hardware failure.

I found no external fasteners (not even under its rubber feet) so I started attacking visible seams with iFixit opening pick and opening tool.

After a symphony of snapping sounds announcing death of many plastic clips, top lid came free. We can see a Seagate BarraCuda 3.5″ HDD. It is from their “Compute” product line for general personal storage usage. Usually with a two-year warranty, so we’re right on time.

Speaking of warranty, there was an interesting piece of text on the label that I don’t think I’ve seen elsewhere before. “HDD sold as component of OEM solution and not for resale. The product warranty does not cover HDD if removed from OEM solution.” If the warranty hadn’t already expired, I guess I’ve just voided it.

Many more snapping of clips later, the external enclosure has been separated into three plastic pieces: top, bottom, and a frame sandwiched between them.

RIP, plastic clips.

Vibration dampening rubber knobs sit between the external frame and screws fastening the HDD to a folded sheet metal tray.

Once those screws were removed, the drive could be slid off the tray. I was surprised to see such a large expanse of circuit board; I had expected two small boards with a ribbon cable to bridge them.

Removing two screws allowed the circuit board to be removed. All physical connectors (SATA, power, USB) are on this side, as are a few through-hole electrolytic capacitors.

The other side is sparsely populated with surface-mount components.

I didn’t see any visible signs of damage that might explain why Ubuntu “cannot enable” this device. Not that I would necessarily know how to fix it, anyway. This was just for curiosity. I might as well look around now that I have this in my hands.

I noticed three identical copies of a circuit, but beyond that, I don’t know what it does. Why would the circuit board for an external hard drive need three of something?

The largest chip on this board is a GL3520 by Genesys Logic, a Taiwan company specializing in USB solutions. The GL3520 is no longer listed on their website, but their GL3523 (which I infer to be its successor based on model number) is listed as a USB3 hub controller. This is consistent with integrated USB hub functionality.

The next largest chip is the ASM1153 by ASMedia, another Taiwan company. ASM1153 is a USB to SATA bridge and its presence is completely expected within an external USB hard drive product.

But now with the enclosure removed, this Seagate BarraCuda Compute 8TB drive has been transferred to the PC with a Rosewill hard disk drive cage so it is now an internal drive. It was successfully detected as a SATA device, and by running “zpool import” I was able to mount it to my Ubuntu filesystem. I copied a few files as tests, and they all seemed intact. Then I ran “zpool scrub“, and no errors were detected. I take this to mean that my data has survived which is great news. I want to keep using it as my TrueNAS replication backup, but I don’t want to dedicate my PC tower to this task. Fortunately, I have an old Dell Optiplex 960 that should suit.

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