7200/75 PSU

Hunt down an ATX power supply with the right dimensions (which will be a little challenging, since it is not the common ATX shape) and adapt it to the Mac. You'll need a couple of molex connector housings and pins and an inverter to convert the power on signal. I think instructions for the adaptation are on xlr8yourmac.com. They probably don't have an article about the 7200 specifically, but the 7500 uses the same power supply, and the 8500 uses the same pinout, with a differently boxed power supply.

But that way you can use a new power supply and not a used one whose components may be about to blow.

Of course, that may be too much work for a 7200/75... But if you build your adapter as a dongle, basing it on an ATX extender, which will plug into the supply end of any ATX supply, you'll never need to do another adaptation. Just plug in your adapter, install the ATX supply and go.

The first thing you really should do with a 7200 is to dump the motherboard and get a 7500/7600 style board. If you have damaged components on the board already from the bad power supply, it doesn't make sense to keep using it or to fix it.

Not worth the time investment into a 7200 board. Get a 7500 board instead.

buy a whole new 7500 ?

I say fix it, just to say you did. Unsoldering a chip and then putting one in is -not- that hard, and if it works, woo!

If not, you say it does, then secretly get a new powersupply, and throw the old one off the bridge with some cinderblock shoes. or... cable ends..

oops, I forgot to mention, as far as I can tell, the logic board is fine, I blew the PWM controller from inside the PSU. I have had no options to start up the computer so I cannot tell if anything else is damaged.

If you are blowing PSUs that frequently, have you considered having your mains supply checked? Do other electronics fail on you?