Anyone here good at troubleshooting or reviving a possibly dead hashing card? I had the "red light" issue with a batch 3 unit and while I disconnected the power supply to replace it I found out my replacement power supply was missing a second EPS 12v connect (ie CPU connector) so I plugged in a power supply from a batch 2 unit. When I tried to start it up the typical giving up the ghost smoke came out of the the third card - not a lot of smoke but it was noticeable. The unit of course refused to power on. With the third module disconnected the unit powers up just fine. It even power up just fine with it's original PSU.

Could I have killed it trying to swap the power supply or was it most likely already dead (due to the red light warning) before I tried to mess with it?

If anyone had this happen to their batch 3 unit I'm wondering if you can tell me what the exact cause was. Was it blown capacitor(s)? I looked at the exposed side of the board and no obvious burn marks or dead caps are visible. The smoke appeared to have come from the top of the backplane near where the power connector is, but from underneath.