Quote from: gablay12 on July 30, 2015, 08:30:04 PM

I have a similar problem with S5.I have sent a board to Bitmain.They will check.I have never over clocked.

I have measured the voltage of working and not working board.I have found the problematic chip by this way.If a chip is malfunctioning the board does not work.

I recommend you to measure the voltage of first and last chips.

Today, I can not access to the miner.I am suspicious of a virus which effects miners.

Which "chips" are you talking about? Voltage regulator or something? Do you have a picture?

I have the same problem with an S3. One minute it was working, power cycle, and now although the firmware boots, the network works, etc, it will not start hashing. Fan and ASIC status are blank. cgminer says "No devices detected!"

Edit:
The S3 has what looks like two 3.3V test pads and one 1.8V test pad on the control board. They all test good.

Edit:
Upon further investigation is looks like one of the hash boards is bad in my S3. It will hash at half speed with the one good board but the other board doesn't seem to work. Why would a whole hash board go bad? Hmmm... I'm not sure what the protocol/communication is between a hash board and the PIC32 on the control board. I know it's not the control board though.