[docb77]

My computer has developed a problem. It won't boot up any more. It will power on briefly, but then shut down before it boots into windows. It worked just fine before, but now I can't access anything. I was able to get into the bios once, but haven't been able to since.

I figured that it was likely either a power supply or motherboard issue. So I swapped the power supply (pc power and cooling silencer 610) for another that I had on hand that works (antec true power trio 650). Same problem.

Needless to say I'm not all that excited about swapping out a mobo. Does anyone have any other ideas of what it could be before I go to that extreme?

Mobo: MSI Neo2-fr
cpu: Core 2 Q6600
GPU: Geforce 9800 GTX
Case: CM Cosmos

[pcstudent]

I had this problem just a couple of weeks ago and it turned out to be a defective PSU. Since you have already swapped the PSU out and still have the same problem, I recommend that you try troubleshooting the issue with the motherboard manufacturer's tech support. Most likely, however, I believe you will need to swap out the motherboard if the problem is with the motherboard not sending a "power good" signal back to the PSU in order to post and boot. Just my two cents' worth.

[teh 1337 haxxor]

You could try plugging into a different outlet. Other than that, it looks like a mobo swap is the next best thing.

When you say it starts to boot, does it show the BIOS, or do the fans simply spin and nothing is displayed on the screen, and then it powers off. Does it beep at all?

[docb77]

it varies a bit how far it gets before it shuts down. Sometimes it's almost immediately after the fans spin up, but usually it gets close to where it would boot into windows.

[freak720]

just to cover all the basses are you sure your cpu heatsink and the thermal paste are installed correctly?

[docb77]

thought about that, but it doesn't seem like enough time to overheat.

[teh 1337 haxxor]

It heats up much quicker than you would think it should. The TPD of the Q6600 is around 130 watts. The mass of the CPU is quite small in comparison to a heatsink (heats up faster), with little surface area without the heatsink (very little heat is dissipated). Therefore it heats up much more quickly and reaches a much higher temperature.

While the CPU is probably not overheating, the motherboard detects that the CPU is heating up abnormally fast (and it does if you don't have a heatsink properly installed on it) and shuts the computer off so that it doesn't ruin the CPU.

[docb77]

Isn't the shutdown point close to 100 degrees? I would think it would take longer than a few seconds even without a heatsink present. At any rate, it was working fine for almost 2 years before this started without any heat issues, still, easier than a mobo reinstall if that's really the cause.

[teh 1337 haxxor]

Like I said, the motherboard will should automatically turn off the computer at boot if the CPU temp rises too quickly, as if the CPU heatsink is not properly installed. It doesn't matter how hot it gets. It matters more how quickly it heats up, which is quite quickly.

[SeVeN]

I'm going exctly through the same problem. After a couple of tries I can get it to boot into Windows. As a matter of fact, I'm replying to this post using the same computer. I've done my troubleshooting and I'm sure it's not the PSU in my case. So I'm left with the CPU & mobo, and I don't have much options as far as repalcing any of them. Assuming I have a bad CPU, would I have unexpected shutdowns? Would a bad CPU allow me to boot into windows & have my PC work fine through-out a whole day? Or does it sound more like a mobo problem?

Sadly, I own a Tyan Thunder K8WE (server mobo) supporting 2x Dual Core Opterons 275. One of the best systems I've built, but I can hardly find a replacement for either the mobo or the CPU's.

Thanks for your help in advance.

[knelson276]

I used to have a similar problem to yours, turned out was a memory socket problem, every now and then would have to re seat the ram, often just pushing down on the ram and giving it a wiggle would be enough to allow the computer to boot and work fine for weeks. think the problem stemmed from dissimilar metals causing oxidation on the contacts. other troubleshooting tips, disconnect or remove anything you don't have to have to boot. sound cards, video cards if your main board has a built in graphics chip, unplug any unnecessary usb connections. i had a computer that wouldn't boot with a just 1 particular usb thumb drive plugged in. spent several hours tearing my computer apart before i figured that one out. good luck