Desperate question: The PC spontaneously turns itself off.

[Hydr0gen]

Please can anyone give me an advice on what exactly happens, what is the cause and what should I do if the PC suddenly deactivates and is not possible to turn it on unless unplugging it and waiting for several minutes?!

I cannot express how frustrated I am...

It happened more than once, during prime95 test and even during WinXp setup (from boot). What is really weid is that nothing major was really happening. In fact, I wanted my brother to learn how to reinstall a PC and we were just staring at the screen where you choose an install to repair or make a fresh new one, when it happened

Several guys suggested it might be the power supply. I got eurocase 300W. I tried two calculator for optimal power supply, with the first one suggesting 270W and the second one only 230. So I should have enough...

By the way, my HW is:Athlon XP 2000+, 768 MB RAM 333 MHz, MSI KT4V, ATI Radeon 9500 128 MB RAM, HDD IGM 60GB 7200 rpm, LG GSA 4120, CD ROM Tohsiba 40x. Using WinXP SP1

 

[Xenus]

Did you change or add anything new recently because if you did that is most likely your problem.

 

[MasterBaiter]

I'd guess that it's either a choking PSU or something is getting hotter than it should be getting.

 

[mczak]

Re: Desperate question: The PC spontaneously turns itself of

Please can anyone give me an advice on what exactly happens, what is the cause and what should I do if the PC suddenly deactivates and is not possible to turn it on unless unplugging it and waiting for several minutes?!

Definitely sounds like PSU trouble. Now, 300W ought to be enough for your system, but the wattage number isn't everything in a psu which counts...
Especially the part about unplugging it and waiting sounds to me like some protection circuitry in the psu got triggered for whatever reason - I got similar results when I short-circuited a PSU .
Other possibilites would probably be a defective board or something causing short-circuits in your case. I'd definitely lean towards a defective power supply though.

mczak

 

[Guden Oden]

Is the PSU fan running? If it overheats the thermal protection might trip and hence make the unit unoperable until it cools down again.

It could also just be plain faulty. Try another PSU.

If problem persists, it sounds like a mobo problem.

 

[_xxx_]

Having to unplug and wait == heat. The PSU should be sufficient if working properly. You might also want to temporarely disable UltraDMA in your BIOS when installing Win, since some mobos have problems with that (Epox 8Kxxx series for example) and be sure to install latest chipset drivers.

 

[Hydr0gen]

To begin, thanks for your suggestions.

I think I tried to check the power supply's temperature by simply touching it and it didn't seem hot, just warm.

Anyway, I think I'll hand it over to guys at the shop I bought all the components, the guarantee is still applicable.

btw.: I haven't been at home since, so I couldn't try anything.

And by MB drivers you mean the common software or new bios?

 

[mkillio]

It could be a bad Hard Drive

 

[Moffell]

Had the exact same problem with bad capacitators on a motherboard that was roughly the same age as yours. Check to see if any of them are bulging.

 

[Hydr0gen]

Eh... Stupid I know, but what exactly are capacitators ? I am not an english native...

edit: If capacitators are those lil' barrels, then they seem ok. Same with everything else . I did not burn my fingers when touching stuff inside the case (cpu and gpu fan, the supply...). Btw.: prime95 is running at the very moment!

It might sound a bit weird, but prime seems to crash the hole thing when I turn off the monitor and go away(happened more than once).

 

[MasterBaiter]

Capacitors are kinda like baby-batteries. They store energy for very short periods of time though, and also help to stabilize (purify) the current a motherboard (or any other component for that matter) gets. You will notice caps are typically located around the cpu of the motherboard and some around the memory slots.

 

[Vadi]

Don't want to nitpick but capacitors store the current until they get discharged.

 

[MasterBaiter]

Don't want to nitpick but capacitors store the current until they get discharged.

Actually they aren't known for long term storage (over time they will discharge on their own (leak current). Some of the big dudes take quite awhile to discharge though. I've heard of guys getting their butt-hair fried after trying to work on monitors without properly discharging them. They don't pay me enought to screw with that stuff.

 

[_xxx_]

Heh, it's even more fun with a tube amp, there are some really HUGE caps in there.

 

[Dio]

Oh yeah. The power supply for a 5000W poweramp is basically a toroidal transformer that looks and weighs like a couple of bricks and several chuffing massive caps. Trying to improvise replacements when the cap's been out of production for years is always interesting.