Overclock.net › Forums › Components › Power Supplies › PSU won't start
New Posts  All Forums:Forum Nav:

PSU won't start

post #1 of 3
Thread Starter 
I'm having a problem getting my i5-2500K on Asus P8Z68-M PRO system going. Using a Seasonic 350W PSU which by itself (green wire to ground) works with all voltages OK, when connected to mobo won't start. Only CPU with HSF is on board, 2 sticks RAM (or none). Simulating start button by direct shorting PWR switch connector, the PWR_OK (gray wire) signal stays low and everything is dead (xcept 5VSB). Various online PSU calculators agree that my system (just integrated video, 1xHD, 1xBD burner)will need around 240W, OC'd maybe 290W. Seasonic has 2 17A 12V branches. Mobo has 8 pin CPU power connector, PSU just 4 pin. Somehow, from reading around, I don't think that makes a difference. I wonder if I can trust the calculators or just assume that PSU perhaps can't handle the initial surge and I need higher power unit. Anybody has any experience with PSU rating? Also, will bare mobo (no CPU, no RAM) produce some POST beeps?
post #2 of 3
That is a gross overestimation, for 240W you would need to add something like a 6770 to that system... I doubt the PSU is the problem, have you checked the mobo and CPU with a different power supply?
post #3 of 3
Thread Starter 
This calculator http://extreme.outervision.com/psucalculatorlite.jsp and Overclock.net's own PSUCalc 1.11 both come up with similar results around 240 - 290W (with 40% OC). And yes, I should do the obvious, troubleshoot by substitution. It's just that at this stage I don't have a bunch of parts to substitute. A few PSU's I own are from the 5V/3.3V days, no spare i5's or LGA1155 mobos. I guess it's time for RMA...
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Power Supplies
Overclock.net › Forums › Components › Power Supplies › PSU won't start