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No POST, 5 short beeps on old system

Last response: in Systems
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September 22, 2011 7:14:50 PM

My dad's computer suddenly failed to POST, so he brought it to me. Here are the symptoms: every fan spins, power Led on the motherboard is lit up but I never hear the beep indicating POST and there's nothing on the screen at all (the monitor seems to receive something, because it switches on from standby and displays a blank screen, then goes back to standby)

Following the advices on those threads:

(This one is a huge 23 steps guide)
http://www.tomshardware.com/forum/261145-31-perform-ste...

(Referenced in the above guide)
http://www.tomshardware.com/forum/262730-31-breadboardi...

I took everything out of the case, reset the CMOS and tried to post with only the CPU and HSF (Power supply was properly connected and I used a system speaker). I then heard three long beeps, this beeps seem to loop for a long time too.

Here's where it gets weird, the next step is to add one stick of Ram, so I did. I powered it on, waited (it took longer this time than with only the CPU) but finally heard 5 short beeps, then nothing. I tried all the Ram slots, cleaned the Ram's contacts, tried all the Ram slots again with the other Ram stick and got the same results every time.

Here's a quote from the 23 steps guide:

"If you get the long beeps, add a stick of RAM. Boot. The beep pattern should change to one long and two or three short beeps. Silence indicates that the RAM is shorting out the PSU (very rare). Long single beeps indicates that the BIOS does not recognize the presence of the RAM. If you get the one long and two or three short beeps, test the rest of the RAM."

This doesn't mention 5 short beeps at all, I checked what Asus's support had to say about the motherboard (Asus P4P800) and here's a quote from them.

From: http://support.asus.com/Troubleshooting/detail.aspx?SLa...

The article mentions trying to post with the CPU, RAM and GPU.

Memory issue: Beep (1 long 2 short)

Graphics card issue: Beep (1 long 3 short)

CPU issue: Beep (5 short)

This makes me think that the CPU is bad, but since I hear the beeps when I try to post with only the CPU it should be fine right?

My next step was to add the other ram stick, still 5 short beeps. I then added the video card and a monitor. I heard no beeps at all this time and the monitor's screen was blank.

I tried adding a keyboard and mouse but it changed nothing.

I even measured every pin of the Power supply connected to the motherboard (while everything was in the case and out of the case) and the voltages were fine (12.22V for yellow etc). I compared my readings to the ones from this site.

http://pinouts.ru/Power/atxpower_pinout.shtml

Am I right to suspect the GPU? I don't want to buy one and suddenly discover that it doesn't correct the problem. I'm concerned about the 5 short beeps when I add the Ram though. I don't have any other Ram that I can try either (old DDR1).

Here are the computer's specs (this is a very old system).

Motherboard: Asus P4P800
RAM: AzenRam DDR Pc2700 (2x 256MB sticks)
CPU: 2.4Ghz P4 (exact model unknown)
GPU: Asus Nvidia 6800 with 512MB of memory
Power supply: Hi-Power 480W

Thanks for the help, if I forgot to mention any detail, please ask me.



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September 22, 2011 9:07:35 PM
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thyrokio said:
Am I right to suspect the GPU? I don't want to buy one and suddenly discover that it doesn't correct the problem. I'm concerned about the 5 short beeps when I add the Ram though.


Great old system except for the low amount of ram. I remember those P4 2.4s overclocked pretty well ;)  I believe that board uses a BIOS made by AMI so you are right in thinking that 5 beeps indicates a CPU problem. Not at all sure what the 3 long beeps you get indicates, 3 short would be bad 64k onboard memory (this is different from your RAM sticks). Since you are getting 5 short fairly consistently you may have a bad CPU or as unlikely as it may be, the thermal compound between your CPU and its heat-sink may have flowed onto the pins/socket causing a short. Not very likely, but you could try reseating your heat sink. Your POST codes don't indicate a graphics card issue. Maybe find a friend who will GIVE you an old AGP graphics card to test it with - I'd happily give you one of mine if it was feasible...
September 22, 2011 9:32:10 PM

I did reseat the CPU, the old thermal compound was completely dried up, so I replaced it. If any of it flowed in the socket, it would have happened long ago (when it was still vaguely liquid-like). Could it be something like a capacitor or a Mosfet around the CPU?

I guess I really need another P4 and test that huh... I get the 5 short beeps after I put the ram up until I put the video card on the system, it stops beeping at all at this point.
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September 23, 2011 2:04:10 AM

Problem solved! (sorry for the double post...)

I went to the local flea market, bought a very old and crappy AGP card for 10$ plugged it in and TADA! it worked... I put everything back in the case and it's still working.

The five short beeps were just a fluke after all...
September 23, 2011 2:04:25 AM

Best answer selected by thyrokio.
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