Yes, I've mucked about with them.
A common failure for them is the DC-DC converter in the middle of the board burns out, and the chips no longer get the ~1.2v rail. The symptom of this is the board being alive and looking like it's working, but finding zero FPGAs when probed (bfgminer -d? --detail) will show you the FPGA probing step, and if you get zero on a board that has cards, the DC-DC converter is bad.
If the board is /totally/ dead, and doesn't power on the fans or start flashing the red "alive" LED, the fuse on the backside is likely blown - I've seen this more than once, and I believe it to be the result of an insufficient power supply. Voltage sags, amperage increases, the 5A fuse blows. Jumper it or replace it.
I have spare parts around and a bunch of known good parts if you're interested in having me test a few, or just selling them without having to remove the FPGAs. I used to swap dead MMQs for working ztex 1.15y clones, but I'm running out of those.
PM me if you're interested.