Hi- I will take mine apart today and see what is going on in there.

Last night I started the two using 250mhs and 800mV  and they have been running at 62.5ghs pretty nicely. about 12 hours later the one ZOMBIED.  I also created even MORE cooling to the heatsinks in like a custom wind tunnel design...

So I will take it apart and clean it. I have very good expeirence in electronics so I wont noob this up. Also got all the correct tools and liquids etc to do a proper job.

I suspect it wont help... the next route after this will be a powered USB hub. And I will connect that hub to the PC without the 5V channel and let the HUB power the units. Also put them on a 4 hour timer. turn of for 15 minutes and restart the whole thing. If I turn of the USB hub power then that should emualte pulling out the cable and restarting the MCU on next power up. I got all this on a sperate power adapter so I will just turn everything off, restart cgminer with some scripts and restart it. Then I can keep these settings at 62.5ghs and it will have some short resting periods (i hope that wont cause to much PCB strees) and it will restart and keep running till the cows come home.

OH- by the way, the same thing happened to me when it droped from ~60 to ~45 because of the voltage settings. Recomended is close to  800mv using a nice PSU like a computer one. I run mine on the stock PSU (240v) using 790mv and it got hot but didnt melt but that worried me so I just found and old PC and pulled the PSU and hooked it up to that. Its more effiecient any way and keep it at 800mv now.