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Computer turns off for unknown reasons

February 13, 2010 at 06:25:56
Specs: Windows XP Pro
Problem: After a few hours of being on, my computer will turn itself off. The green power light on the front of the tower will stay on, but the red light (what I think is for the hard drive) goes off. I bought a replacement motherboard (the same as my old gateway motherboard), but the problem still exists.

What I know:
-Power supply tested good
-New motherboard doesn't like my 512 MB of RAM
-Monitor is fairly new
-Hard drive is new
-It doesn't appear to be a dust problem
-CPU is still the same one I've always had (My computer is probably about 5 years old- Maybe I need a new computer altogether?)
- Everything is plugged in correctly

Since it doesn't appear to be the motherboard, now I'm thinking it could possible be the CPU.

Does anyone know what might be wrong with my computer?


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February 13, 2010 at 06:39:17
U replace motherboard, did u remove the old thermal paste and apply new thermal paste? turn itself off or restart itself? How did u test the psu? How did u know the mobo doesn't like 512ram. And u didn't bother to list the complete system specs.

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February 13, 2010 at 07:06:16
I did not remove the old thermal paste. I did apply new paste.

Like I said in my message, it turns itself off.
I tested the PSU with a power supply tester.

I know the motherboard doesn't like the new RAM because I got this message when I started up my computer for the first time after installing the new motherboard: "BIOS has detected a non-optimal memory configuration. Dual Channel operation requires identical paired DIMMS installed in both memory channels. Changing the existing DIMM configuration can improve systems memory Bus Bandwidth. Channel A DIMM 0 should match Channel B DIMM 0

The two RAM sticks have always been identical to each other and I put them in correctly. However, I don't think it's my RAM that causes my computer to shut down, because in with my old mobo, it did not have any problem with the RAM.

Gateway 310x Desktop Computer
Intel Pentium 4 CPU 2.40GHz
2.39 GHz, 512 MB of RAM

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February 13, 2010 at 07:29:24
I think power supply tester it's not a good way to test psu. And i suspect the psu is bad. So u apply the new thermal paste ontop of old thermal paste. Can u see the cpu temp in bios? U should know, u need to remove old thermal paste and apply new one. Better borrow psu from a friend and test it.

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Related Solutions

February 13, 2010 at 08:11:10
"I did not remove the old thermal paste. I did apply new paste"

There's your problem. You have to completely remove ALL paste from both the bottom of the heatsink & top of the CPU, then wipe them both clean with a solvent such as alcohol or acetone. Once they are wiped, do NOT touch either surface. And when applying new paste, all you need to do is put a small dab, about the size of a grain of rice, in the center of the CPU. Do NOT spread it around. Just leave it as-is & install the heatsink. That's all there is to it. If you did it differently, you did it wrong.

Follow these instructions, regardless of the brand of paste you use & do NOT re-use old paste:

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February 13, 2010 at 08:56:38
Since my BIOS did not seem to have a PC Health option or show any info. regarding the CPU temp., I downloaded a motherboard monitor program from Intel's website. Granted that this program is accurate enough, it says my cooling unit is fine:

Processing zone =51° c
System zone 1=41° c
System zone 2=44° c

The PSU; however, has an alert notice.
Where it's supposed to be +12v, it is 13.250v
Instead of +5v, it is 5.573v
and instead of +3.3v it is 3.575v

Also, my fan seems to be acting up (I don't have the cover on my computer in case I need to check a part). It is going at very random speeds. When I first start up the computer, it goes at it's fast, normal speed. Later on, it will go at a much slower speed and sometimes will stop, only to start up at the slower speed again a split second later.

It looks as if it can't make up its mind at what speed to go.

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February 13, 2010 at 11:53:16
The voltages are WAY out of spec so either the program you're using is inaccurate or your PSU is garbage. You should still mount the heatsink properly, especially if you re-used the old paste & added more on top of it.

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