maybe a psu problem?

[hootch]

I have a faulty mobo that won't display anything. I tried all the suggestions about resetting the bios and etc., and sometimes when I power on the computer it'll start for a second or two then it'll turn off then start back up to the no post. I'm wondering if that delay in turning on is due to the psu (which is 400w) or due to the faulty mobo?

 

[stevty2889]

Could be any number of things. Why not list your system specs to make things a little easier, including the brand of the power supply. 400w is meaningless by itself, a quality 350w PSU is superior to a generic 400w PSU, and the rating of the 12v rail is very important for modern systems. Is this a new build, or something that was up and running, and suddenly stopped working?

Several things I have seen that cause your exact symptoms:
CPU not fully seated
No fan plugged in to CPU fan header
Motherboard not mounted properly on standoffs(ie a standoff is out of place shorting to the motherboard, screwed motherboard directly to case without using standoffs, loose screw under motherboard).
Bad power supply

Try booting with the bare minimums. 1 stick of ram, video card, CPU/Heatsink and Fan. If that doesn't work, try with the bare minimums, but remove the motherboard from the case, and put it on a non-conductive surface.

 

[Jiggz]

Does the unit even stays on like fan's spinning and drives whining? If it's not then try the suggestion from Stevty. If it is but the there is still no video then check you video card make sure it is properly seated and the connections properly connected.

 

[Trizik]

sounds like the PSU to me