Quote Originally Posted by bikepete View Post
Minor progress last night - opened up one of my donated Dell ATX PSUs and armed with a multimeter started looking around for the ground-to-case connection as per the various instructions around e.g. here. Aiming to link three PSUs to give a 36V 10A supply.

Turned out to take about ten seconds - just follow the black wires back down to the PCB and there was an obvious jumper (J23) over to the case via a screw. Bit awkward getting in to cut it so ended up desoldering and pulling it out with needle nose pliers. Checking after with meter revealed it did the trick, so I did the second one as well.

Still a bit of wiring to sort and need to get some power resistors to provide a bit of load for them to go at but that's the main hurdle over I think as far as the PSU goes.
Doesn't need much of a load. 100mA on each +5V rail is usually sufficient (50 ohm, 2W).