Computer shuts off by itself.

A brief history of the computer and the current issue. I built my parents a computer a few years ago for Christmas. Nothing fancy, since they primarily only surf the web, email, face book etc. About a month ago they mentioned that the computer would shut off all of the sudden. At first I thought it was a registry issues with XP. I ran a couple of utilities to see if that resolved it. A couple of weeks ago, I get a call saying that XP will not load because of a corrupted file... I try a few things and basically thought it would be easier to just recover the pictures, docs and things they want to keep and do a fresh install of XP.

Which brings me to this forum. I have successfully removed all of the data that my parents were interested in keeping. I reformatted the drive, and reinstall XP. It still is shutting off, not really letting me too far past the XP splash screen. I have reseated all of the cables, and memory. I was hoping for some advice before I started throwing money at it. I built the whole thing for about $350, used an old case I had lying around that had a PSU. I am not ruling out that the PSU might be bad, but don't what to buy anything unnecessarily.

 

I wonder if there might be an air bubble/s trapped in the thermal compound between the CPU and the heatsink. (In the past you needed to take some covering tape off the compound on the heatsink before you installed it and some people missed taking it off, I don't think they use covering tape any more though.)

Note that you cannot just take the heatsink back off and reseat it without replacing the thermal compound.

Is there any chance the heatsink is not locked down securely?

Could the CPU not be compatible with the motherboard? Check at the motherboard manufacturer's website.

Go into the BIOS at (a cold) startup and check the temperature readouts. Run some programs (especially something that you have seen cause it) under Windows, then re-start and check the temps again. In the BIOS you should see settings for what temperature the system shuts down when overheated. See if the restart temperatures are close to the shutdown temps.

There should be voltage readouts in the BIOS, although I had one motherboard that had one bad voltage readout, but it ran perfectly for around 7 years.

Matt

 

Were all the air intakes and exhausts cleaned out before installing the new motherboard? Some of the air intakes might be hidden behind the front cover. Edit: You might need to install extra fans.

An old PSU quickly becomes "underpowered" for modern hardware. Modern hardware can be quite power hungry, although they are becoming eco-conscious. Try using a power calculator
http://www.journeysystems.com/support/calculator/

Matt
"An old PSU quickly becomes "underpowered" for modern hardware ", they are now producing 1500 Watt power supplies, OMG!

 

Thanks for the replies.

I cleaned the case good before I put the new pieces in, however, I was shocked to see how much dust had accumulated in the case since I built it (about 3 years old now). I cleaned all of the dust out, even took the front off the case and cleaned a screen filter etc. So, it is free of dust at the moment, but still shuts off.

Though I doubt the PSU of that wattage would be under powered since I didn't put anything in that would draw more power than the original mobo and drives... just newer. However, I am not discounting the fact that the PSU is the culprit.

I doubt that there would be any issues with the thermal paste because I haven't taken the heat sink off since it was installed 3 years ago. If that was the problem, I would think that it would have had problems before now.

I have never run into or heard about "buldging caps ". What should I be looking for to rule that out or confirm that is the problem?

Based on the help so far (thanks btw), I am leaning more towards replacing the PSU.

 

For the "bulging caps ", the capacitors are the cylindrical components that stand up off the motherboard. Check that the tops are flat.

You can borrow a power supply from another (similar...it needs the same motherboard connectors) computer for testing. Check it has a higher Wattage.

 

Agreed. If the plastic tape was left on, you would likely have had heat related issues from the start.

I agree with starting with the PSU (assuming the system is clean of heat trapping dust and dirt, and all fans are spinning freely). Many assume that fans spinning and lights lit proves the PSU is working fine. But fans spinning just means the 12VDC is there and lights mean the presence of +5VDC. That does not mean the required +3.3VDC is present nor does it prove that any of those voltages are within required tolerances, or stable.

Sadly, if it has not been cleaned in 3 years, permanent damage may have already occurred. I generally recommend inspecting monthly, and cleaning as necessary. This is especially true if there is smoking or pets (especially cats) near the computer. Long exposure to excessive heat is a major cause of bulging or leaky capacitors, although they certainly can and have failed with normal temps. Note that most of these electrolytic caps will be surrounding the CPU socket.

If the board is less than 3 years old, call the maker. Even if a little over 3 years old, you might get lucky and they may RMA for you. Gigabyte replaced a 4 year old board for me - they even paid shipping both ways and it was a 3 year warranty.

Motherboards can be recapped, but it often is not cost effective and a new motherboard is often the best solution. Those that advertise solid or solid Japanese capacitors will not leak. Unfortunately, if the Windows license is for an OEM license, you will need to buy a new license too unless you replace the board with an exact replacement (or recommended replacement by the original board maker). This is because an "upgraded" board is considered a new computer.