A530 power supply connector pinout

[Lockon_15]

I read somewhere CD32 has same power socket, but make that double checked.
 
http://www.ianstedman.co.uk/Amiga/amiga_hacks/Amiga_Power_supplies/body_amiga_power_supplies.html
 
Scroll down low and you'll find 2 great pics of CD32 connector which should be the same as A530. After you verify current working condition, you might consider bypasing A530 power gate in order to drain power from A500. It worked in my case, but only when I replaced power hungry SCSI HDD with CF.