G4 mobo fried??

OK... have a G4 Quicksilver 2002 820-1342 mobo with 933 processor (133 Mhz bus).

I bought a second-hand 661-2591 Dual 1Ghz processor module, after being assured it would work.

I fitted it... it didn't boot.. I re-fitted the 933 module... it doesn't boot. White button lights up when the machine is powered up, then goes dark.

Questions:
1. Is the 1Ghz module NOT compatible then, and have I fried my system?

2. Could it be the PSU?

3. Any other ideas?

Blimey... one dead mac :((((

A couple of things to consider:
1) Did you press the CUDA switch after you set the processor? On the QS it is near the PRAM battery.
2) Did you ground yourself and the QS while working on it? Were there any static sparks? That would be the worst case scenario, that you damaged the mobo.
Since #2 would be fatal let's hope for #1! Put the dually in, press the CUDA button and hold it down at least 5 seconds. For good measure you can hold the ?-Option-P-R keys to reset the PRAM. A few chants and/or arcane gestures wouldn't hurt either.

Ah, the QS mobo. It is very fragile. I have broken several. My issue was dropping a screw, yeah a screw, which scratched one of the traces. NP. Number 2 pencil and repaired. It worked fine for a while...but I was doing some serious overclocking with no concern of breakage. It finally died. Tried the pencil again and no go. So, with that, scan over the traces just in case...mostly in the large empty part of the mobo.

-maestro