Hey compy geeks, assistance por favor

Hello

So new lappy is fine, but I am working on someone else’s dead computer and while I have some skills in the dead desktop arena, I have come to the end of that skills set. If I get this thing fixed, i get a new winter coat out of the deal. So yay.

Here’s the history.

Compy was having some power button issues. Button would stick and wouldn’t let the thing be turned off sometimes. Compy got turned off. Several hours later an attempt to turn it back on failed. Nothing, no juice, no start. Just dead.

It’s decided that the power supply is the most likely culprit. New(ish) said to be working one is procured. Correct attachments to make the 20 pin into a 20/24 pin are purchased. I go through and disconnect and reconnect each connection one at a time from the old power supply to the new.

Nothing happens.

Talked to guys who built the compy originally and they recommend hot shorting the jumpers. Find the jumpers from the power button, disconnect, stick a screwdriver in to complete the circuit and turn on power. The fan gives half a lazy spin, but the compy does not start (btw, everytime the compy is on the green motherboard light is lit, so some kind of juice is getting to it.

FTR, I did change the power cord and where the cord was plugged into first.

I’m heading out to radioshack to buy a multimeter so I can test both the old and new power supplies. But if they are both working then I have no idea what to do next. Compy seller says he doubts it’s the cmoss battery (and I think I remember the cmoss battery doing the turn on/ turns off right away thing when it dies, not the no power at all thing).

So geeks, what do you think I should do next?