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PC does not boot, fan works - CPU blown??

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February 4, 2010 8:43:27 PM

Hi,

Apologies if this is straight forward, but after searching various troubleshoot guides etc I am still stumped.

The issue I have is as from today my PC no longer boots up. Symptoms/signs after I press the 'on' button are:

1. Exterior lights/leds come on.
2. Fan starts and continues to operate.
3. The PC does not give the usual bleep after a few seconds as the CPU kicks in and signals go to the monitor.
4. No signal to monitor at all.
5. If left, the fan wil continue to whirl indefinitely, boot light on front of PC flashes intermittentely.
6. Disk drive release switch does not function (thought it could be an operating system fault)

It has worked fine for a number of years and I haven't downloaded anything, added new software/hardware recently. All leads (power/monitor) have been removed and replaced. I opened the casing and have to admit, the fan was fairly well caked in dust which I removed but the PC still gets no further. Also the problem seems sudden, no previous failed boot-ups.

I am guessing the CPU may have blown, but it powered down fine last night so seems a bit strange. For whats its worth its a Pentium 4 processor and runs on Windows XP

Thanks in advance,

Neil
February 4, 2010 9:56:15 PM

I guess the obvious thing is to check that your vid card is 'seated' properly , I have had this issue many times and know of others who have , it sounds like everything is functioning but you aint getting a video signal .. so try that and make sure all vga leads etc are properly connected , sometimes they just need a wiggle
a c 134 à CPUs
February 4, 2010 10:48:40 PM

Examine the capacitors on the motherboard, if they are domed or have brownish gook coming from them then they are bad. badcaps.net has some pictures on the right side of what bad caps looks like. they should all be nice and falt and clean.

Related resources
a b à CPUs
February 4, 2010 10:54:20 PM

Another thing you can try is to reset the bios to it's defaults. See if the system will boot this way or not.
a b à CPUs
February 5, 2010 6:27:08 AM

PSU
February 5, 2010 6:33:18 AM

What someguy said - sounds like PSU to me.
Vary rare to blow a CPU
February 5, 2010 6:55:59 AM

Memory, PSU or Motherboard. Try to remove everything; PCI cards, video card, memory. If you still don't get the POST error beeps, most likely you have a defective motherboard or PSU (test with a spare PSU).
a c 93 à CPUs
February 5, 2010 10:45:21 AM

Sounds like motherboard.
February 5, 2010 4:14:38 PM

Thanks for all the assistance so far. Here's where I am with getting this diagnosed:

I stripped it right down and followed the 'breadboarding' guide. Nothing happened until I removed the video card, wheeby I started to get the bleeps as suuggested. I have now put it all back together (including video card, do not have spare) and the system now appears to boot up normally, however I still get no signal to the monitor.

Is there any further ways to make sure it is the video card that is faulty before I go out and purchase another??? I have wiggled it as well to make sure it is seated properly!!!!

Cheers, Neil
a b à CPUs
February 5, 2010 4:23:04 PM

neilbunty78 said:
Thanks for all the assistance so far. Here's where I am with getting this diagnosed:

I stripped it right down and followed the 'breadboarding' guide. Nothing happened until I removed the video card, wheeby I started to get the bleeps as suuggested. I have now put it all back together (including video card, do not have spare) and the system now appears to boot up normally, however I still get no signal to the monitor.

Is there any further ways to make sure it is the video card that is faulty before I go out and purchase another??? I have wiggled it as well to make sure it is seated properly!!!!

Cheers, Neil


Still could well be the PSU - it may not have enough power to power up the video card and the PSU sounds more likely the cause than the video card. - do you have a second system (or a friend with a system ) that you could try the video card in (that would at least tell you if it was the video card !)
a b à CPUs
February 5, 2010 4:31:31 PM

+1. If the psu is shot it will not have enough power to deliver power the pci/agp to power the card. It will also lack the power to power up the cpu. But the rest of the stuff like fans will still work. As stated is the best thing to do would be to either try the video card in another system or borrow a another card and try it in your system.

One thing I forgot. Does the monitor say its not getting signal or is just staying black? If its the latter it is just a dead monitor.
February 5, 2010 5:02:11 PM

Well I rule the monitor out (runs fine with my laptop). Also I think the PSU might be ok, I'm sure its powering the CPU through its boot sequence (by the recognisable noises the PC makes!!). Would the PSU be able to power the CPU and not the video card??

Plan is to nip to PC World tomorrow and buy a cheap video card (currently have a NVIDIA Geforce 7300, so no great loss)
February 28, 2010 9:13:42 PM

I was cleaning my computer from the inside but I didnt put the fan on the processor properly so the computer started slowing down. I then opened the computer up again and put the processor fan on properly after struggling with it for quite some time but now my computer starts up but gets no signal to the monitor. I have tried everything, I am not sure if the motherboard is faulty because I struggled to put the cpu fan on and did touch the capacitors once or twice or if the processor has blown because i forgot to put the fan on the first time.
March 1, 2010 12:53:47 AM

I have a home pc with an Intel D865GVHZ motherboard and 3.06ghz Pentium CPU (running linux).
The system has been working fine until a power outage last week. I wasn't around for the outage. Apparently the power was out for about 10 minutes. All other computers restarted fine when the power came back.
1) When I press power, nothing happens.
2) I disconnected the 20pin connector from the motherboard and connected a power supply tester. The tester indicates the power supply is fine and when I turn on the tester, fans and harddrives that are still plugged in start.
3) When I connect the 20pin connecter to the motherboard, I notice that a small green light lights up on the motherboard.
4) When I press the switch, nothing turns on, not the CPU fan, no other fans, no hard drive, nothing.
5) Thinking that the switch may be bad, I cut the switch wires and touch the wires together and nothing.
6) I looked over the motherboard and don't see signs of any blown resistors or anything.
What do I do next? Do CPUs get blown by power problems or is it likely the mother board.
!