i'm not sure if I understand. you need power for HDD, not a590?
just use the multimeter to check the pinout. iirc, two in the middle are probably GND. so you're chances are 50% anyway..
perhaps those very old hdd use different pinout? (I know that is the case with 3" floppy drives, for eg.)
Yeah trying to power the HDD, but my old PCB had a different power connector, the new PCB has a standard molex connector and on the bottom of the PCB has two pins (2 and 3 from memory) soldered together with a wire.
Have tried what was suggested above but fried the 20MB XT drive. My new plan is that I've ordered an ATX kit and will bypass the internal power connector and use an ATX PSU.
Have some mods that I want to do that will require more power connectors anyway so have made the jump to ATX earlier than planned. Just have to wait on shipping now. :-/