Hardware repair of dead USB flash drive memory stick

Have a 64Gb Lexar USB flash drive – will not register.

When insert it slowly into port, the red lights flash briefly when partway in, then go dark.

When insert quickly, just very dim brief flash of red light and then dark.

Drive will not register. Looking back, I realize that unit was gradually getting harder to read as when jiggled it by accident was ejecting and then having to be reinserted to mount. I believe that what did it was getting tweaked a little too much (bent a little while inserted) which I actually thought had damaged the USB port itself, but the port is fine - the USB memory stick is not.

Opened and looked at it, no observable damage. I did not attempt repair yet. Haven't looked at it with a 40X magnifier yet.

Sliding it into USB port does not seem to harm it, as I’ve done that repeatedly and the port still works fine with other USB flash drives.

All software recovery attempts have failed, including with advanced recovery software.

I suspect that the problem is some discontinuity between the USB port and the chip, at least I am hoping it is just that and not that chip is burned out.

It is common for the solder to fail on the USB connector to PCB connection.
It is also common for a person to make a real disaster with a soldering iron.

I remove the plastic case and hope for the best. Re-solder the connections. Remove the solder short I made. Solder again. Curse several times. Then just before I give up it starts working. Then I can't find the bottom half of the plastic case. Quickly copy all the data to a hard drive. Spend 20 minutes looking for a new flash drive. Give up and drive to town. Forget why I am in town. Get a large soft drink and come back home. Three days later; "Why is your soldering iron on the kitchen table?"

Thanks!

Yes, looks like I need to dig up my soldering iron and give it a shot. I was going to try to attach the wires from a USB cable to the dots, but after reading what you wrote I am hoping that just touching the spots with solder will do it.

Is it possible that the connections - at the solder points - are not the issue, and that somewhere between the contacts inside the plug/connector (the contacts that hit the USB port in the computer) and the soldered points is the problem? i.e. that the plug/connector on the chip board itself has gone bad?

CromeYellow said:

Is it possible that the connections - at the solder points - are not the issue, and that somewhere between the contacts inside the plug/connector (the contacts that hit the USB port in the computer) and the soldered points is the problem? i.e. that the plug/connector on the chip board itself has gone bad?

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It's possible, and sounds like it could be the case, given that you had different outcomes depending on how far in the connector was pushed, etc.

You can try reworking the solder points, but next step would be to replace the USB connector (or solder on a new cable, as you said - just be careful to get the wires in the right order)

A friend told me of a story where the USB connector destroyed his port due to burrs on the contacts.

Right, but I have pulled this USB stick in and out of the same port dozens of times the port still works fine did not burn anything out. I also tried it in different ports, USB stick did not work but the port remained fine. Anyway, I am going to get busy soldering not today, but soon!

CromeYellow said:

I am going to get busy ......... not today, but soon!

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Said that many times.

I actually got motivated and worked on it today.

Hasn't worked out so far. I looked carefully under the 40X LED magnifier, thought I saw one connection point that looked a little lifted. I tried tap re-soldering each of the four connections, and even the two on the sides, didn't help. Now I've removed the entire USB plug, and will have to try microsoldering the four wires from a USB cable on to the contact points, but the contact points don't look so good now that I removed the plug, so it may be a lost cause, at least for someone who doesn't really know what he is doing.

This USB stick was backed up about two weeks ago, so all I am losing is two weeks of work, so it's more of a project than a dire need, but I haven't given up yet.

It is teaching me not to rely on these sticks and keep them backed up though.