Motherboard replacement

I would checkout the asrock 790AOD 790gx ($99.99 plus shipping at newegg). I believe it is one of the boards that will unlock the 4th core of the tri-core phenoms.

There is a very good chance that, originally, either the motherboard failed and took out the PSU or vice versa.

Having said that, I wouldn't just plug the Antec PSU into another motherboard without doing a little testing first.

Try to verify (as well as you can) that the PSU works. If you have a multimeter, you can do a rough checkout of a PSU using the "paper clip trick". You plug the bare PSU into the wall. Insert a paper clip into the green wire pin and one of the black wire pins beside it. That's how the case power switch works. It applies a ground to the green wire. Turn on the PSU and the fan should spin up. If it doesn't, the PSU is dead. If you have a multimeter, you can check all the outputs. Yellow wires should be 12 volts, red 5 volts, orange 3.3 volts, blue wire -12 volts, purple wire is the 5 volt standby. The gray wire is really important. It sends a control signal called something like "PowerOK" from the PSU to the motherboard. It should go from 0 volts to about 5 volts within a half second of pressing the case power switch. If you do not have this signal, your computer will not boot. The tolerances should be +/- 5%. If not, the PSU is bad.

I own an Antec 550 TP3 and it's a pretty good power supply, but I suspect you may have a problem with yours. About the only way you are going to get arcs 'n sparks from a motherboard is if the PSU protection circuits do not electronically shut the PSU down.