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techman
01-26-03, 01:51 AM
My son and I had a strange thing happen. His computer was working fine the night before. The next morning he tried to boot and the fans came on but no post beep. After trying new memory and a new power supply, we took the board out of the case and set everything up on my work bench. It booted once. The second time gave 3 beeps but refused to boot. Pulled the plug out of the PS. Put the plug back it would boot. As long as we remove power to the board between boots it works fine. If you try to shut it down and reboot without removing the power, nothing but the fans. I have inspected for Case shorts and all the other usual. Set bios to both optimal and default settings. By the way, he did not have the troubleshooting leds that come with the board installed. I told him to do that, we will see when he does.

Computer AMD xp 1800, MSI k266a pro board, geoforce 2 64 meg video, 40 gig HD. 400 watt PS.

Bios problem?

loop2kil
01-26-03, 01:57 AM
Could be a bad psu or mb going bad. what kind of psu do you have and is it old?

Ken
01-26-03, 10:42 AM
Yes, give some more power supply details... If you can get into BIOS, post what the rails are doing...

techman
01-27-03, 01:24 AM
brand new power supply 400 watt atx.... old one was 250 watt atx. Replacing the power supply did not change the problem.

§I€MFKR™
01-27-03, 01:27 AM
I've seen bad CMOS batterys do stuff like that. For the couple dollars i would toss one in there and see what happens. It looks like you already cut out alot of the hardware from the mix.:)

techman
01-27-03, 01:28 AM
Ken, I am not familiar with the term "rails". By the way I talked to a fellow with the same problem but different mb and setup. Could this be a cpu problem? It runs fine once it is booted but you must shut down power by total disconnect. Any electrical engineers out there? I was wondering about some ground loop kind of thing.

techman
01-27-03, 01:30 AM
Thanks, Hybrid, We will do that. The battery tested 3.4 volts. But who knows, worth a try.

§I€MFKR™
01-27-03, 01:33 AM
Yeah, You never know, It would make sense why the rig runs good after its running. And they only way to get it to boot is to remove all power.:)

loop2kil
01-27-03, 01:44 AM
Im thinking the power phase contoller on the mb could be bad too.

terrancelam
01-27-03, 01:45 AM
hmmm..firstly Try clearing the c-mos. Maybe you enabled something that should have been. Usually when a motherboard won't turn on even though the fan spins, usually on of three things,

A.) Cpu is dead/cpu fan plug isn't working; thus it doesn't allow the computer to run at all.

B.)Videocard is dead/ not inserted properly.

B.)Ram is not compatible, Dead or Not inserted fully.

techman
01-27-03, 06:10 PM
CPU and motherboard can't be dead because if we reboot after shutting down power, it works ok.
Hey, loop2kill, what does the power phase controller do?

techman

loop2kil
01-28-03, 03:02 AM
Originally posted by techman
CPU and motherboard can't be dead because if we reboot after shutting down power, it works ok.
Hey, loop2kill, what does the power phase controller do?

techman

M/b can be 'going bad' meaning its just a little flakey...but the power phase controller is what the uses to control what comes from the psu(i could be wrong here). But if that is going bad then the issues they are having would make sense.