Two out of them is harder to get them start mining, at the very first beginning. and it become harder and harder with each reboot. These two eventually cease to operate yesterday, until now (but still viewable in cgminer console)
I got 2 boards that won't boot up (2nd led keep blinking) but once I turn on the AC to cool the room they boot up in about 1 minute. After that they will hash just fine even with AC off.
When a board first starts up, the firmware makes sure the board and chips are cooled down before it starts the self test. This helps ensure the maximum number of engines (cores) will pass self test.
LED decoder ringThe LEDs are numbered 1 to 8 with #1 closest to the USB connector and #8 closest to the power and fan connectors. During first power up, LEDs 5, 6, 7, and 8 will light up and LEDs 1, 2, 3, and 4 will indicate a failure code if anything is wrong with the hardware. This happens
VERY quickly - in less than a second.
If the initial hardware checks are good, #7 will blink indicating it is waiting for the board to cool down. This will always blink for a few seconds even if the board is cold.
Then #7 and #8 will blink indicating ASIC self test.
After that, 1, 2, 3, 4 will indicate how many jobs from cgminer are waiting to run in the input queue. LED 5 is just a debug output for me but it roughly indicates a job has completed - but sometimes blinks too fast for the human eye to see. Just ignore LED 5.
I am working on some firmware updates that will fix most (or all?) of the problems the boards are having. For example, one failure I think I have figured out is occasionally a board will jump to more than 100 GH/s but have 100% hardware errors. I have one board that does this once per day or so and needs to be rebooted. After chasing this for a while, I believe I have finally figured out what is going on and will have a fix in the next release.
