USB Flash drive repair

My guess is your connections are not all there. if anything else were damaged I think you'd be able to see it. What are you going to connect the jumper wires to? Do you have a spare connector? I think I would solder the end of a cable to the board so you have a USB connector on the end of the cable. I'd like to have that on flash drives anyway. They stick out too much from the laptop and are prone to damaging the machine when bumped. My previous laptop lost two of its four USB connectors that way.

On Thu, 1 Oct 2015 13:39:50 -0400, bitrex Gave us:

You can also try booting a Linux Live CD or DVD.

But it still sounds like one of the connections is not yet re-established.

The heat gun method is bad.. You don't have a soldering iron? You can also remove the connector and solder on the wires of a cut off USB cable to it, permitting better access to said connections after the typically shrouded connector has been removed. Wires are usually easier as then they can be attached individually.

I do have a soldering iron...;) But the only thing is that there is so little space that it's nearly impossible to get in there and resolder the pads, even with the finest tip, and ensure I'm not creating bridges while the plug is still in place. I think I'm going to follow your suggestion (and what I was thinking) and just remove the connector completely and use a spare USB cable as the header.

On Thu, 1 Oct 2015 13:45:20 -0400, rickman Gave us:

Another indicator that you ain't too bright.

Nice copycat job too.

I've detached the USB header completely and the pads on the data lines appear to be completely lifted. Do the data lines on flash drives usually have resistor pull ups or resistors inline? There are what looks like two 0402 resistors on the underside that I think might be connected to the data lines that I might be able to attach wires to.

When the board is all chewed up, this is the most likely way to fix it. Absolutely not worth it to just make it useable, but you may be able to get the data off it this way, with careful handling. it is likely to be real fragile with the cable soldered on to it.

Jon

Keep working on the idea of getting a better USB connection, but also take a close look, under magnification if you have it, at the flash memory chip itself. At least on some older flash drives I have taken apart (1GB-4GB or so), there was a small controller chip that spoke USB, and then a standard-ish flash chip for the storage. If the controller chip is there, but the connections to the flash chip are damaged, you could well get the problem you describe: the controller wakes up enough to convice the OS that something is there, but the controller is unable to come up all the way because it can't get at the flash memory.

I have held in my hand a drive that was damaged this way; it was whacked hard enough that many pins on the flash chip lifted from the board. The owner decided to start with (older) backup copies of the documents that were on the failed flash drive.

Matt Roberds

I suggest getting a flux pen and name-brand solder braid and trying what's called "drag soldering". There are videos on youtube of the process. It's as magic as it looks, but the flux and clean solder is mandatory.

I'd carefully dismantle what's left of the USB plug and clean up the solder pads for its pins. Next - wade in with an illuminated strong magnifier and try to identify whether any tracks leading away from those pads are broken.

Its probably easier to cut the plug end from a USB extension lead and wire that onto the flash drive PCB. Cutting the lead from a scrap item like a printer that runs from a separate supply probably won't work - they usually don't have the supply pin wired in the USB plug/lead.

I'd glue the busted thumb drive and the cable to a piece of wood, to protect the cobbled connections.

Joe Gwinn

On Fri, 02 Oct 2015 16:32:30 -0400, Joe Gwinn Gave us: .snip

Tie wraps.

On 2015-10-01, bitrex wrote: [thumb drive repair]

Drives of this type often have separate storage and usb-interface chips. the symptoms you describe could be explained by a USB connection that's working and storage that isn't.

Could be a solder joint, pcb trace, wire bond or die failure.

On 3 Oct 2015 09:28:25 GMT, Jasen Betts Gave us:

Except that the entire initial failure was simply the connector.

How is it suddenly that you think connections elsewhere are severed?