Member Avatar for kumara1234

A dead PC, green mobo light on, VGA fan spinning, no processor fan
I think I’m having a very serious issue. I've had my PC for 3 1/2 years, and it's been working just fine in this period. However, now it had absolutely no signs of life (nothing on the display). When I remove the casing, I can see a green light on the mobo is on but the CPU fan not spinning. However fan on the VGA board is spinning. Is this a sign of burned processor?
Does anyone have any ideas what I should try to solve the problem?
The machine has processor (Intel P IV 2.6 Ghz HT) on the Intel 865PERL motherboard.

I appreciate your help.

Thanks,
Ruwan

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Dani AI

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A concise diagnostic path that builds on and s suggestions but avoids needless part-swapping.

First, a cheap, safe test narrows the problem quickly: plug any working 3-pin case fan into the motherboard CPU_FAN header. If that fan runs, the header is delivering power and the original CPU fan or its connector is the likely fault. If it does not run, the CPU 12V feed (the 4-pin ATX12V) or the PSU is suspect — a simple PSU-tester or multimeter check of the +12V rails will show that. If live-voltage checks are uncomfortable, stop and get a tester or professional help.

Do a careful visual inspection next. Look for bulging, cracked, or leaky electrolytic capacitors and any scorch marks or brown residue around the VRM/CPU area — those are strong indicators of motherboard failure. Also smell for burned electronics. Fit a small chassis speaker to the motherboard speaker header and listen for BIOS beep codes at power-on; no beeps with a known-good speaker usually means it never reaches POST.

Two quick, low-cost extras: briefly short the two front-panel power pins on the board to rule out a faulty case power switch, and try a PSU bench or paperclip start only to verify the supply actually brings the rails up (attach a fan or HDD to give the PSU a load). Interpretation: header alive + spare fan spins but no POST → likely CPU or motherboard failure; header dead while PSU rails are good → motherboard problem; PSU rails low/out-of-spec → replace PSU.

Safety note: avoid probing live connectors without experience, use anti-static precautions, and don’t remove/reseat the CPU unless confident and prepared to reapply thermal paste correctly. A cheap fan and PSU tester will usually tell you which direction to go.

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Member Avatar for Rik_

If this has only happened after you have moved it then it is most likely not something serious. You need to remove and refit your ram and all cards.
Let me know how you get on. :)

Member Avatar for kumara1234

If this has only happened after you have moved it then it is most likely not something serious. You need to remove and refit your ram and all cards.
Let me know how you get on. :)

Thanks for your quick reply.

Yes, I heard about the idea of remove and refitting the RAM. So I will definitely try it later (at the moment I have a decent laptop for my works :) ). Moreover, I’m expecting some more ideas.

Again thanks.

Member Avatar for Rik_

What I suggested is only the first stage in fixing a problem like that.

You can also remove and refit the graphics card plus all other cards in there.
You can remove and refit the CPU.
Reset the cmos.
And check all power cables.

Member Avatar for RJCO

first remove your processor and clean the dust and fit it again and buy new CPU Fan and install...then it will work fine...that's it...
enjoy

Member Avatar for kumara1234

Well, some positive ideas, But I have a busy schedule in next few days. What I want to say is I’ll update this thread after doing those experiments. So thanks for your replies.

Member Avatar for kumara1234

I have another question. Would a failed fan cause the computer not to turn on at all? (This Intel mobo (865PERL) has a CPU temperature monitoring system. Software called 'Intel Active Monitor' was included with the mobo CD. It monitors the fan speed and temperature.)

A source says that some motherboards won't boot if it detects that the fan speed is too low or it detects a dead fan.

Member Avatar for Rik_

That is true, a lot of motherboard won't boot unless they can detect the fan spinning.

Member Avatar for kumara1234

By saying 'a lot of motherboard won't boot', did you mean nothing shown on the display like in my case.

Member Avatar for kumara1234

Processor Issues
No boot situations can be caused by any of the following.

...

If the processor overheats, the system may not boot or may shut down shortly after booting.

  • Make sure the fans on the processor are connected properly and running.
  • Make sure that the thermal interface material or the thermal grease is applied to the processor properly.
  • Make sure that the power supply fan is running properly and any other external case fans are running properly.
  • Make sure that the air intakes for the external fans are unobstructed and have at least several inches away from walls and other items.

This is what Intel website has to say about my motherboard (Intel 865PERL). Therefore, I hope and wish my CPU fan died peacefully.

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