GA P35c DSR3 will only boot with antec earthwatts 650

[bobkat]

system specs:

e6750
ga p35c dsr3
2 gb crucial ballistix ddr2
8800 gts 320

so this system had been running fine for more than a year. i rebooted last week and then the system would not boot. No signal to the monitor, no beeps, nothing. I switched video card and memory out to no avail. Then i bought an antec earthwatts 650 PS to test out if the PS could be the problem. Sure enough the system booted up. I wanted something nicer so i bought a corsair 750 watt power supply with 60A on the 12 v rail and it will not boot. It will not boot with my old OCZ power supply either. I also bought a modular thermalright power supply and that didn't work.

The only power supply that the system boots off of is the antec 650. I don't understand it ...

I can reproduce the no screen symptoms if i don't plug in the 12v CPU connector with the antec 650 power supply ... so i'm sure it's something to do with the power to the CPU. I just don't understand what gives, any opinions?

Cheers!

 

[bilbat]

Jeeze - this is really bizzare. The only thing I can think of offhand is to grab a magnifying glass and a flashlight, and carefully examine the power connector pins on your MOBO. Slim chance, but I recently ran into a bad pin in a modular harness from a Zalman 750; I'm kind of picky, and have a habit of 'clip&solder' to adjust all my wiring to length, so I use a continuity meter to check EVERYTHING prior to power up; found an intermittent 'open' on a floppy power adapter, & traced it back to a malformed pin in the Molex on the modular cable - fortunately, they gave me more than I needed, so could swap it out. The difference between your PSs may be how tight they 'grip' the male pin...

Good luck!

Bill