So I checked out the ebay unit I got - one board was completely dead, no lights whatsoever. The PS showed the orange right-side light. Voltage 0 across the leads from it. The other one was working.
I pulled the cooling and put it on my 50% dead board, no go, still dead.
So I guess some of my chips are fried? I need to re-read what carman says above.
Anyway, I replaced my board with the good ebay board and the cooling system which came with it, all is well.
One odd thing - when I initially tried the ebay machine and noted the dead board,
I measure voltage across the dead unit and the working unit - as mentioned, the
dead was 0 but the working one was at 18+vDC ?!
I should have measured again after I got it all back together, but it took a long
time and I forgot. Will check it next time.
Also, I took your advice carman, I slathered the things in thermal paste, I forget what,
some decent stuff. They are running well, quite cool.
Glad the new thermal compound worked out for you. As for your totally dead board, power it up on a car battery using my instructions a couple pages back. One big spark, one pop and a few seconds later and you will see the board light up save for one dead core. If you want you can then replace the bad mosfet otherwise just run it on 7 cores. You won't get the orange light anymore after you short it. Just make sure you get the polarity correct.