New build 10 second reboot cycle! Won't POST

[tigerlilycs]

I am really hoping someone can give some ideas on this one. I've hit a brick wall and I'm hoping I don't have to take it in to the local shop for a fix!

Here are the specs:

MSI P43 Neo3 mobo
Core 2 Quad Yorkfield Q8400 CPU w/ heatsink
Tiger 500w PSU

The rest of the components aren't really important at this stage because the above is all that's connected. Also, the mobo is not installed in the case. I have it sitting on it's cardboard box outside the case.

The problem is that when I power the mobo on, the PSU and heatsink fans spin, the LED's come on on the mobo and it stays running for 10 seconds then shuts down...reboots and runs for 10 seconds then shuts down again. It continues to do this until I manually power down with the power button. Here are the things I've tried:

-Checked to make sure all 4 heatsink clamps are tightly secure
-Swapped the 500w PSU (which has an 8-pin CPU plug for a new 300w w/ a 4-pin CPU plug (thinking the PSU was bad)
-Reseated the CPU
-Reset the bios
-Removed the battery and put it back
-Verified CPU/mobo compatibility w/ manufacturers
-Removed the LED pin headers
-Made sure all power cables are plugged all the way in
-Swapped power strips
-Applied thermal paste to CPU

I even took it the local shop to have the CPU and mobo tested and they tell me both are good and it booted up and hit POST and continued to run on its own until manually powering down!!! Yet when I brought it home it won't stay on again! They tell me they used the exact same components. Am I possibly just doing something wrong here? Yes I can take it back to the shop but I can't keep spenind the money to do that.

I would appreciate ANY suggestions or ideas. Pleeeeease can someone help me?!

Thanks!!!

[RicheemxX]

Quote:

Here are the specs:

MSI P43 Neo3 mobo
Core 2 Quad Yorkfield Q8400 CPU w/ heatsink
Tiger 500w PSU

The rest of the components aren't really important at this stage because the above is all that's connected.

For starters you need to have at least one stick of memory installed, and well if you want to know its booting you need to have a gpu installed as well.

Tiger PSU?? What are the specs on that, that would be my first guess.

edit: From the looks of it that was already a suggestion from your old thread

When you reseated the cpu and applied thermal paste did you make sure to clean of the old and not use too much? It should only be a thin layer!

[tigerlilycs]

I did have 2 sticks of memory installed, then i removed one and tried again...then i removed both and tried again. I tested each stick by itself as well.

In regards to the PSU...I did have a Rosewill 500w originally which made the high pitched noise. After my other post I returned the Rosewill and bought a new 680w Tiger at the local shop, which doesn't make the high-pitched noise btw. ) Sorry I put the wrong wattage on my first post)

It was a new CPU so there was no thermal paste to remove and when I did apply it I made sure to center it and only use a thin layer. I also made sure none had leaked over the sides onto any contacts.

I also originally had a gpu installed but it doesn't stay on long enough for anything to come up on the monitor. I get no beeps, no video...nothing. 10 seconds flat and it shuts off. I initially had all components installed...CPU, GPU, RAM, HD, DVD/CD. When I first turned on the new build and it shut off after 10 secs I began removing all the components one by one and testing it, until all I had left was the CPU and PSU. When I remover the CPU it stays on. When I put it back it started the 10 second thing again.

[RicheemxX]

The CPU wouldn't have thermal paste but the heatsink would have but that really doesn't matter as much.

Sounds to me like either you don't have all your power connections made or your psu isn't giving the board enough power. Double check that you have to 20+4 connected as well as the 12v 4pin mobo connection connected.

Double check the cmos jumper, make sure its in the correct position. Install one stick of ram and your gpu and go from there.