Computer loses power

[Jonestown]

Having a strang problem with my parents computer.

The computer was working normally yesterday, but now when I go to turn the computer on, it starts up, but then gradually loses power until it stops and shuts down. The fans start up and then eventually stop and the system won't stay powered on longer than 10-15 seconds.

I'm guessing the obvious culprit is the power supply. It's an Antec Smart Power 350 watt, no problems before.

The system isn't a power hog. Just an athlon 64 3000+, VNF4F mobo, HDD, DVD Burner, and an X300 video card. Nothing that this PSU shouldn't be able to handle.

Any ideas?

Jonestown

 

[Seekermeister]

What do you mean by "gradually losing power"? Usually, if there is a power loss, it happens all at once. When it shuts down, is it always at a consistent point...like during or after the Windows logo screen? Why I'm asking is to see if the problem is a totally hardware, or software issue.

 

[Gautama2]

Something like this happened to me also, and it had an even stranger solution. Unplugging the front panel hd audio case cable from the mobo fixed it.


EDIT: Bah, didnt read that it worked before.

 

[dBTelos]

I'm with SM, usually power issue result in very sudden power loss (like someone pulled the plug, if ya know what I mean ). I think it might be dust building up in the case causing overheating. Clean out the case with compressed air.

 

[Jonestown]

Don't think it's an overheating problem, as the comp has been off for several hours.

It starts normally (fans spin up, DVD drive initializes), but then the fans slowly lose power, and the comp just shuts off.

Again, it won't stay powered on for more than a few seconds.

Thanks for the help so far.

Jonestown

 

[Gautama2]

Could be the outlet, plug something else that uses a lot of power into the outlet and see if it happens to it.

 

[dBTelos]

Does the HSF have thermal paste on it? I could see this exact thing happening from an overheating system. Clean it out with compressed air!

 

[Operandi]

Given Antec's recent failure rates that would be my first suspect.

Originally posted by: dBTelos
Does the HSF have thermal paste on it? I could see this exact thing happening from an overheating system. Clean it out with compressed air!

it's a cold boot so heat would not be an issue.

 

[Jonestown]

I've been able to get into Windows 1 out of 10 times or so, but I can't find the common problem.

Thought it was a faulty power switch, so I swapped the power button with the reset button on the mobo, but still the same problem. I reseated the video card and RAM, no joy.

I'll check the thermal paste (built this comp a 1.5 years ago worked perfect until the other day).

Since I have been able to get into Windows occasionaly, the mobo and cpu probably aren't the problem. Once in Windows, everything seems fine.

To get the system to even try to boot, I have to unplug the comp from the wall, then try again.

Thanks for the help so far.

Jonestown

 

[dBTelos]

I've had many systems where the CPU temp. would rise so quickly that about 5-10sec after power on, the system would shut itself.

 

[Seekermeister]

If unplugging it makes a difference, then the problem is likely the overvoltage protection in the PS.

 

[Operandi]

Originally posted by: Jonestown
I've been able to get into Windows 1 out of 10 times or so, but I can't find the common problem.

Thought it was a faulty power switch, so I swapped the power button with the reset button on the mobo, but still the same problem. I reseated the video card and RAM, no joy.

I'll check the thermal paste (built this comp a 1.5 years ago worked perfect until the other day).

Since I have been able to get into Windows occasionaly, the mobo and cpu probably aren't the problem. Once in Windows, everything seems fine.

To get the system to even try to boot, I have to unplug the comp from the wall, then try again.

Thanks for the help so far.

Jonestown

Sounds like a power issue of some kind, if you do a search here you'll find Antec failures are not uncommon. If you have a spare PSU try that otherwise it might be a good idea to pick up inexpensive unit to keep around for testing purposes. You can pickup a very decent FSP for under $30.

I wouldn't bother checking the thermal compound or heatsink unless you've physically changed something in that area, heatsinks don't just stop working for no reason.

 

[Lemon law]

Will it boot to dos---or a cd---or something like a knoppix OS--there is a large amount of software that will determine if its a windows loading issue--or something unrelated to windows. Thats always step one in similar situations where it gets beyond post.

But if its in hardware---one place to start is with a VOM and voltage checks---then on to memory modules and swapping out various boards.

Troubleshooting is never easy---but eliminating possibilities is always the goal.