Computer won't power on

I just replaced my stock Intel heatsink with a Thermalright SP-94 and changed my power supply from a 420 W Vantec Stealth to a 500 W AeroCool Aero Power 2. I also replaced all my case fans with new LED fans. Everything seemd to go fine, but when i tried to power on the system after I was done, nothing happened. None of the fans spin, including the fans in the PSU. The only indication of power being connected is the STR LED on the motherboard. I've tried a different power supply, and I've tried booting with only the heatsink and RAM installed. None of this has worked. I've been troubleshooting this now for the better part of last night and today, and could really use any thoughts as to what's going on. My specs are-

Intel P4 3.0 Processor
Intel D875PBZ Motherboard
Twin Kingston Hyper-X DDR400 RAM modules (1 gig)
Western Digital Caviar 250 GB Hard Drive
AeroCool Aero Power 2 PSU
Thermalright SP-94 Heatsink with Vantec Spectrum 80mm Fan
Raedon 9800 Pro Video Card
Sound Blaster Audigy 5.1 Platinum
Coolermaster ATC-210 Case
Plextor PlexWriter Premium CD-RW
Sony 16x DVD
Windows XP Home Edition

 

a few quick suggestions, let me know if you've already tried them:

1) reseat the video card... thats a main reason for not booting very often

2) make sure the power button and all the rest of that junk is connected to the motherboard from the case.

3) check that all vital components are securely plugged into the power supply, including Motherboard and Video Card

4)try swapping the RAM sticks... try 1 at a time etc..

 

if you still have no luck, cross your fingers while removing your thermalright beast (i love them ) and hope you did not accidentally crack the core of the CPU during installation... it rarely happens, but it does.

if you have the patience to check the CPU and reapply thermal compound when you put back on the SP-94... give it a try

 

I've double-checked all the power connections, both the 20 pin main and the 4 pin 12v, and they all seem fine. I did pull off the heatsink to check the CPU, and it looks alright to me, but then again, I've never seen a cracked CPU core so I'm not quite sure what to be looking for...I thought it might have been the power button on the case, but everything looks alright, and I did try putting everything into a different case. My real concern is that nothing is happening when I hit the power button...and I mean nothing. I can hear the PSU humming slightly when I turn its switch on, but no fans, no CPU power up, just that lone motherboard LED. This would be a lot easier if I could at least get the thing to POST and get some beeps, but I can't even get that. I'll check the vid card and the RAM and see if that works. Thanks for the tips so far.

 

The connectors are set right, I've checked it a few times and re-done it a few times now just to make sure, and I've also tried moving everything to another case that I know has a working power button...I'm running out of stuff to try, but thanks again for the help

 

have you tried clearing the BIOS?

certain motherboards will respond as you are describing until the BIOS are cleared... just another thing to check

 

Have you checked the 120/240 volt switch on the power supply?

 

Voltage switch looks good...looks like I'll wade through Intel's support section to figure out how to clear the BIOS and see how that goes.

 

you should have a jumper near the motherboard battery. It usually reads Clear CMOS (which holds your BIOS preferences).

once you move the jumper to the 'clear' setting, to be certain you can also take out the battery for about 20 seconds. then, but the battery back in and move the jumper back over to the default setting and try booting.

if it boots, you'll obviously have to go change your BIOS settings as they will be on default.

 

Ok, I can only find one jumper, and it's for BIOS Config, with the options of Normal, Config, and Recovery...should I just pull the CMOS battery, or should I keep looking for another jumper?

 

i just took a look at your motherboard manual, and i dont see the standard clear CMOS jumper either... i gues Intel does it differently.

anyway, try setting it to Config. if nothing happens, set it back to normal and remove the battery (of course having the system un plugged the whole time)

 

Yea, I tried all 3 BIOS jumper configs, and nothing worked. I've got everything unplugged now and the battery out, Intel says 10 minutes should clear everything, so hopefully that will work.

 

Well, still nothing. I'm absolutely out of ideas now, and I'm completely at a loss as to what the problem could even be...does anyone know if you can have a dead motherboard even if you get a STR LED turned on?

 

one last suggestion for now... make sure the motherboard is seated correctly on the standoffs (or tray, if you have one) and not coming in contact with the case. any contact can cause it to short out, making it not boot, an possibly doing damage.

 

well, after going through all of that, i finally broke down and ripped apart another machine and stole the cpu. Apparantly, even though I can't see any cracks, mine is dead. Thanks to everyone for all your help...i'm off to make a late-night processor purchase.

 

bummer be very careful mounting the sp-97 on the new one... dont want a repeat!