Hi

I have a computer running windows XP which i built myself a couple of years ago. Ive often done this, and had no problems. Sadly, that doesnt mean im clued up on tech stuff! Last night i was happily playing FM09, as you do (lol) when the computer turned off. Not shut down, turned off - just like it would if you pulled the power cord out. It did not restart itself. I thought 'hmmm' and pressed the ignition button or whatever its called on the computer to power it up again, and hey presto it fired up as normal. Windows loaded, and while it was loading the desktop icons, it turned off again. I pressed the button again, it started to boot up then turned off again before getting as far as windows. Ive opened up the computer, cleaned it all out (i wondered perhaps there was dust creating a short circuit or something?), but even now it still isnt working properly. In fact, now it will turn off within a few seconds of me turning the computer on. I cant do anything with it at all.

Any ideas? Thanks in advance.

Paul

i wondered perhaps there was dust creating a short circuit or something?

Not unless abnormally moist, or full of metal dust. Dust just creates a heat-trapping blanket.

If there was a lot of dust and heat buildup, something might have been permanently damaged.

I would start by making sure you have a good power supply. I use a FrozenCPU Ultimate PSU Tester for power supply (PSU) testing when I am away from home. It is not as good as a qualified technician testing the PSU under a "true" (realistic) load with an oscilloscope or power analyzer, but close. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you can better detect a "failing" PSU, or one barely within specified tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, not a true load. Alternatively, you can swap out the PSU with a known good one that meets the computer's power requirements.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This then requires poking (with some considerable force) two, hard and sharp, highly conductive, meter probes into the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it.

You need to make sure all your fans spin properly. Also, inspect the motherboard for bulging or leaking electrolytic capacitors. These failed or failing capacitors are a common cause of sudden, but seemingly random system lock ups and reboots. The capacitors look like tall soda cans, many of which surround the CPU socket.

All older motherboards, and many of today's less expensive motherboards use electrolytic capacitors containing a liquid electrolyte. Failing (including flawed and/or abused/over-heated) capacitors literally bulge at the seams due to excessive internal pressures. Extreme (and very rare) cases result in a firecracker type explosion that can really stink up a room. Typically, electrolyte just oozes from the pressure relief points stamped in the tops of the capacitor casings (seen as a symbol or letter). The electrolyte can be caustic to motherboards and flesh. Look for white to dark-brown, dried liquid or foam on the tops or bottoms of the capacitors. Bulging capacitors are a sign leakage is about to occur.

A motherboard with bulging or leaky capacitors can be repaired, but often it is more cost effective in the long run to replace the motherboard.

Before booting up again, I would remove all extra drives, USB devices, and all but one stick of RAM. If it fails, swap out RAM sticks - being careful to observe ESD precautions to prevent damage from static from in body.

thanks for the reply, loads of detail but im not clued up enough to know where to start. Just tried it earlier, and it seems to die after about 15 seconds of starting to boot. Can you simplify a procedure in lehmanns terms for me, to see what to try? i assume disconnect all extras and try to boot it, then take it from there? I really appreciate the reply.

As mentioned earlier, "I would start by making sure you have a good power supply."

i think the one i have is ok, but i dunno how to check it. Actually i do - ill rob one from work for the night Ill let you know how i get on! Thanks

i dunno how to check it

Ummm, I explained how to test it - use a tester, take it to a pro, or swap in a good one.

As far as "borrowing" one from work, you better check with the boss first. The company's liability insurance may not allow it. And, if something goes wrong and the PSU is damaged, the boss may not take kindly to that.

many thanks for your help! turns out it was just the power supply that had dies, put a new one in and we're fine again!

Thanks again

Paul

Great! Thanks for the followup!