I recently bought a lot of used erupters from the marketplace, and the seller included 3 dead ones with the lot.
Plugging them in resulted in usb malfunction notifications in windows, one caused audio playing on the PC to stutter and buzz when one of them was plugged in. Another still kinda worked but got very hot (more than usual) and would throw errors in the mining software after about 10 seconds of mining.
Turns out the source of all the heat was from the CP2102 chip, a USB to TTL serial converter IC. Strange thing to fail on such a device.
For those not familiar with the USB Block erupter design, all they consist of is a CP2012 Silabs USB/TTL converter, an Atmel ATTINY2313 8 bit microcontroller, Octal D-type flip-flop; positive edge-trigger; 3-state and an AOZ1021AI 3A Synchronous Buck Regulator, and of course the BE100 block erupter ASIC
After figuring out the pinout for the programming header on the end, I hooked it up to my AVR Dragon that I bought to flash my BFL Jalapeno, sure enough - I was able to read the ATTINY device signature. The attiny was still alive
Strangely enough, I had some CP2012 boards leftover from a project I did a while ago. So I figured it was worth a shot. I manhandled the PCB a bit and managed to remove the dead CP2012 without destroying the traces too much ( I don't have an SMD rework station)
Somehow I managed to solder wires onto the RXD/TXD traces and wired them into the CP2102 board, along with 3.3v and 5v power to run the rest of the board. Success! It works
If anyone is interested, here's the pinout for the 7 pin header on the end of the USB Erupters:
1 USB 5v
2 ATTINY VCC / 3.3v
3 ATTINY2313 RESET
4 ATTINY2313 MISO
5 ATTINY2313 MOSI
6 ATTINY2313 SCK
7 GND
