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Repairing a USB Thumbdrive

It's astonishing to stop and think about how far data storage has come. Here I am in 2013, and my cell phone, camera and USB thumbdrives collectively hold about 80 gigabytes of data. That may not seem like much when compared to the 4 TB hard drives currently on the market, especially not with the ever increasing popularity of HD video. But on the other hand, a lifetime of writing could easily be held by any one of those devices. Or years of photography. Or the fruits of any number of similar labours. And that means we've created a situation where the failure of a small, cheap, mass-produced flash drive could cost a person an enormous amount in lost work.

But surely the fact that data storage is so cheap means that no one would consider working without a backup of their data...

...right?

Ahh, but as the world changes faster and faster, it seems some things will forever stay the same. And putting off data backups seems to be one of the more sturdy of human habits these days. So it came as no surprise when I was asked to help with not one but two very similar data recovery jobs in one week at The Hackery.

The first job was a USB thumbdrive containing the only copy of a teacher's work. It had somehow been stepped on while plugged into a computer, and this resulted in the USB plug getting ripped clean off. The customer said she had had extremely poor luck finding a company that would even consider a repair, and that the quotes she had been given for such an attempt were astronomical. But the Hackery has a deserved reputation for trying repairs that few others would dare, and I've been fortunate enough to be involved in a great many of them, so we agreed to give it a shot.

The customer brought us the remains of her flash drive in a bag. The plastic shell had split in two and the connector completely removed from the PCB. In her favour though was the fact that she had a matching thumb drive of the exact same model and capacity. If the damage was extensive enough, this would give us the option of transferring the flash chip from one drive to the other.

Into the shop we took the drive. A close examination beneath the magnifying Luxo showed good news and bad. On the upside, the PCB did not appear to have warped, the flash chip had not cracked, and none of the components on the board seemed damaged. On the downside, the solder pads where the jack had connected were totally absent, having been ripped right off of the PCB in the accident. That meant it wasn't a simple matter of reattaching the original USB connector, even though the customer had saved it for us.

On the whole, this was a pretty good starting point. In the past I've seen thumbdrives where the flash IC had been split in two, rendering the data forever lost. In this case though the drive appeared mostly intact. So we looked very closely indeed into the magnifier and figured out where the 4 lines from the USB plug went. Enough of the original traces were present to guide us. That meant we could try connecting to it.

First step was to take the USB cable off of a scrap keyboard. The one I grabbed was a Dell, and its cable was much thicker and sturdier than I was expecting. Good on them, I suppose. I trimmed it down and cut the outer insulation back, revealing the 4 colour coded wires inside. Then I stripped a tiny bit off the end of each to expose metal.

Now I was ready to solder. There was plenty of ground plane left, so that wire was easy to attach. And the +5 line went to a via which was still solid, so while a bit of a small target, I was still able to firmly attach a wire to it. That just left the two data lines. These had virtually no trace left, but the surface mount resistors they terminated in were intact. Two very very small resistors, very very close together. Resistors that small are easy to push right off the board if you heat them for more than a second. It took a dabble of flux and a couple attempts to get them both solidly attached and free of bridges, but eventually it looked good under the magnifier.

 

Here it is after confirming there were no shorts.

 

With how tiny the solder points were, and how thick and stiff the USB wire was, I was worried the joints would rip apart before we could get anything off the drive. For this reason I fed the wires through openings already present in the PCB. It seemed to work well, nothing came apart. The light weight drive ended up suspended by its wires.

All that was left was to test it. Fingers were crossed and the drive plugged into our shop machine.

 

Success! The drive mounted first try, and we were able to copy the contents on to the spare thumbdrive.

 

In the end the customer got her data, and an artistic (in her words) reminder to back up her data. And we charged her literally 1/10th as much as one of the other businesses quoted her. Hopefully she'll have no need for a job like this again.

Unfortunately, others had not yet learned their lessons. Continue on to Page 2 to read about a similar job performed on an external hard drive.

Page created July 24th 2013

Once I had love and it was a gas, soon turned out, had a heart of glass