@swimmer63
I applied the heatsinks to the back of the cards. It's the cards themselves that are getting extremely hot.
Are there instructions anywhere that show how to adjust the voltage using the trimpots?
I'm sure there are but I have the old version of boards with not trim pots.
just turn the trimpot with a screwdriver. 1/8th turn clockwise should increase voltage, counterclockwise reduces. do yourself a favor and use a 10$ multimeter as you go to check the resistance and, when powering up, the voltage