I had someone bring me a 512-MB USB flash drive. Someone had stepped on it and bent the connector. When the connector bent, the key broke and fell out. At this point, it was possible to connect the flash drive into a USB socket in either direction. He said it worked once, but when he tried it on a 2nd computer, it didn't work.

I think he plugged it into the 2nd computer incorrectly, and the +/- was reversed.

I haven't opened it up. I suspect it is a lost cause. Do USB flash drive manufacturers typically include any protection (other than the key on the USB connector) to prevent damage from reverse polarity?

Thanks,
Phil

Hi,

according to my experience there is no protection against reverse power in these devices, at least I haven't seen yet.
It is possible that only the 3.3V regulator got damaged and some filtering elements on the power lines coming from the connector.
U may replace the first one with a 78L33 and bridge the latter and see if it works.
before soldering in the new regulator I usually check the 3.3V power line against short circuit.

regards,
pepe