Problem with boot up, new psu, anyi deas?

[Openingfuel]

Well i got a corsair thx 650watt psu today to replace my old one that supposibly crapped out on me ages ago. Anyway it does work apart from the fact that it doesnt boot up my computer.
Here is what it does:
1.When i trick it into thinking that the motherboard is connected it runs the fans, hard drives ect with ease
2.When i try to turn it on using the start button on the case the fans and lights just flick on then straight again they flick off, well better then my last psu i get about a 100th of a second computer time!

So anyone come across this before or can point me to a link. I have also cleared the CMOS by removign the battery several times.

[Speedy Gonzales]

The on/off switch maybe stuffed / faulty

[wainuitech]

Sounds like a fault in the board or other components someplace.

Remove the plugs from the front header, short out the two pins that would normally be connected to the on switch with a flat screw driver, see if it boots, could be a faulty switch.

If not then Disconnect all Components that are not required - leave only the Motherboard, HDD, Graphic Card if it has one, keyboard mouse, see if it boots now.

The next step will determin in there is something shorting on the PC -

I would remove all the components attached to the board, as well as the board from the PC, place on a bench, making sure the RAM and CPU are in place correctly, connect the KB/Mouse, graphics/Monitor - PSU - ( nothing else) short out the pins again to boot, you should be able to boot into the BIOS, or at least it will complain about no HDD etc.

IF it still wont boot, remove the RAM - try again- as long as it has an on board speaker it should beep indicating no RAM. If not the board may be faulty.

[Openingfuel]

Ok ill give that a shot

[wainuitech]

BTW - can we assume its the same problem as This post , same problem ??

[Openingfuel]

Well it doesnt boot by shorting the pins out and leaving the most important parts so im gona do a bench test of it

[Openingfuel]

BTW - can we assume its the same problem as This post , same problem ??

well thats when it started but i am getting different results with a new psu

[Sweep]

Are we sure the CPU is not overheating?

[Openingfuel]

Well nope still sothing on the bench. The same thing with the fan on the psu just jumping a little bit.

Sweep Re: Problem with boot up, new psu, anyi deas?

Are we sure the CPU is not overheating?

I am sure it isnt because when the pc was working the temps were very low even tho i have been overclocking the cpu to 3.42ghz. The temps were still in the high 30s-low 40s on load and in the 20s idile

[Openingfuel]

also just tested without ram and nothing. I added the speaker and it didnt make a noise. So if this is right about my motherboard being faulty, how sure are you about that???????