Eff, why won't my computer boot up?

[myshtern]

I moved my desktop today and put 2 new case fans in, now it wont boot up. By won't boot up, I mean it won't even run the BIOS. The power supply kicks on, right as the fans turn on, it shuts right off. Sometimes it won't even get to the fans turning on. So it's on for literally .5-1.5 seconds.

Then it just turns off for about 10 seconds, then turns itself back on, and repeats this cycle.

I disconnected and reconnected everything from the mobo. I took the CMOS battery out for about an hour to reset the BIOS. Still nothing.

My only thought is - could it be that the CMOS battery is dead?

[myshtern]

It's a GIGABYTE GA-P35-DS3L with a Q6600 processor

[Street_Kings]

faulty fans/overloading the psu?

Try disconnecting EVERYTHING (extra pci cards, fans, drives) except the video card/cpu/cpu fan from both the power supply and the motherboard and boot from there. If the bios comes up and the system POSTs with the power supply wired into just the mobo, then at least the core of your system is working.

After that, plug in one peripheral at a time and power on, then off and adding another piece and powering back on, etc. etc. until you've found what's causing the problem.

If your system won't power on/POST when nothing is hooked up to the power supply except the mobo, and nothing hooked up to the mobo except ram/cpu/cpu fan/video card, then you'll have to start swapping out core components to see what the problem is.

TL;DR:
I bet the psu is nuked or the new fans are shorting out the PSU.

[myshtern]

I was under the impression that when a PSU goes out, it typically just won't run.

Initially I thought that the PSU was overloaded so the first thing I did was unhook the fans and a DVD-rom but that didn't do it. I've disconnected everything and the core is definitely not working.

It's either a major short, bad cmos battery, or crapped out PSU I think. I think my car key thingy uses a 3.3v battery, I'll see if I can pop that sucker into the cmos.

[Weston-work]

Dead PSU's are pretty common these days, with all of the Chinese crap on the market and all. I've come across a couple myself... one burst into flames while it was off, and the other just died and wouldn't power up much other than the fans.

It's dumb that PSU's cost so much these days, but there is a real reason to pay for a better one, so go out and buy a reputable brand. I'm really happy with the Antec PSU I'm using now... it's damn near silent, and it actually works, unlike Chinese garbage.

[myshtern]

sadly, i think the mobo crapped out :(

[DrJones]

sadly, i think the mobo crapped out :(

Most newer motherboards have some kind of diagnostic tool for showing you the boot progress. A set of LEDs or something that you can look up to see how far it's getting. That usually helps the most.