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P4P800DLX Boot Failure--CPU failed Test

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Wayward_Son

Member
Joined
Nov 10, 2006
Location
Southeast Texas
My friend just called me with a computer problem.

He's running an ASUS P4P800 Deluxe with a P4 2.8 that he built a few years ago. No overclocking, never had any problems with it.

Tonight he went to turn it on. No POST. All case fans and CPU fan spin up, but he gets nothing on his screen. Not a single character. I pressed him on this several times and he assures me that he gets absolutely nothing but a black screen. His board actually has a female voice that reports errors through the case speaker (damn, why doesn't my "modern" A8N-SLI have that feature?) that gives him the following error:

"Boot failure--CPU failed TAP"

OR

"Boot failure--CPU failed TEST"

He doesn't know if it's saying TAP or TEST. Anyway, no POST, black screen, all fans are spinning, hard drive appears to be working.




Any thoughts? I was well out of the loop during the P4 era.
 
Me too

If you figure it out, let me know. I narrowed my problem down to either the motherboard or the cpu. I ordered an old Celeron 478 chip for a few bucks on EBAY and tried it with the new chip, but, same thing. Fans turn on but no beep indicating that bios has passed the memory test. I do not have my speech thing turned on, so I don't have an error code. I don't get a signal on my monitor either.
 
My friend is going to try his CPU in one of HIS friend's socket 478 computers tomorow. If it works, then we'll know it's not the proc. If it does, then we'll know the proc is the culprit.

Today he also told me that he usually doesn't leave the computer on overnight, but the other day he left it on all night long and when he went to use it the next day, he just had a black screen. Rebooted and that's when he realized he had this problem. Seems to me this might also be a power supply issue, in which case I have a brand-new spare Silverstone lying around that we could swap in.

I'll let you know what we find.
 
Your problem looks very much like my problem. My monitor went black and thats when I tried to reboot. I looked at other entries in this forum and some people talked about their southbridge going bad. I thought I smelled something burning when I was swapping parts to trouble shoot. I think my sb went bad. Things do not look good.
Thanks for your reply
 
I saw similar posts. I haven't found anyone on these boards with my same error code, but I saw several problems of overheated southbridges going... well... south. We'll find out tomorow.
 
Finally got it sorted out, but a few things still seem fishy.

He already tried swapping both his CPU and videocard into another 478 rig. Both worked fine. This narrowed down the problem to either the motherboard or the power supply.

I brought over my spare PSU and we hooked everything up. When we turned it on, the computer still failed to boot and we got a black screen (monitor wouldn't even get a green light, no signal from VGA) only this time we got a different error message. It said "System Boot Failure due to CPU Overclock" or something very similar. Strange. At this point it was looking like a motherboard issue. So we took the motherboard out of the case and placed it on a sheet of cardboard, hooked everything up, and tried again.

It worked! Computer booted to Windows as if nothing ever happened! So at this point we were sure it was a motherboard issue. So we started to put the motherboard back in and try booting with my good PSU once again, just to cover out bases. It was then that I found something else out of the ordinary: his particular case has some motherboard standoffs built into the mobo tray. Instead of a flat mobo trray with holes to screw in the standoffs, his tray has a combination of screw holes AND integrated raised standoffs for ATX motherboards. Now when we took his motherboard out of the case, I removed nine screws. However, there are only actually eight raised ATX standoffs, with the ninth one requiring a normal brass standoff to be screwed into one hold in the mobo tray. His case was missing that brass standoff, and when he had originally assembled his computer he had put a screw there anyway and tightened it down, effectively warping the motherboard. This may have been causing some kind of shorting issue which was why my PSU failed to fix the problem when we tried to run everything in his case, but DID fix the problem when we ran the mobo on a cardboard insulator.

Okay, so NOW it's looking like the issue we had was a missing mobo standoff and a shorting issue. I decided to reinstall his motherboard using only the eight integrated standoffs and leaving the ninth hole empty. We then hooked up my power supply, turned it on and voila, we boot to Windows.

Problem solved, right? Wrong. So we thought we had the problem fixed, so we reinstall his ancient PSU back into his case and then turn it on. It fails to boot and we once again get the "System failed CPU Test" message. So we reinstall MY PSU, and it boots to Windows.

So it looks like we have TWO problems: One, for sure, is a failed power supply. I've priced him a new unit that should power the rig with room to spare. But it appears that he may have also had another issue with the motherboard case standoffs causing a short circuit. In either case, he has a new power supply on the way which SHOULD finally get him up and running.
 
Yep, the problem that you had, the motherboard being shorted, causes some motherboards to emit a siren sound.
 
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