P3 reboots when CPU not under heavy load.

geoff · 2007-02-13, 04:28

I have a P3/800 that has developed a strange problem: If it is not running flat out, it reboots. I can boot using a mprime bootdisk and it runs the torture test without problems for hours, but when I stop the torture test it reboots within a few seconds.

The machine is a HP vectra VL 400, it runs as a diskless client using the onboard LAN, has nothing but a floppy drive attached. It ran OK for about 4 months, but now reboots before getting through the network boot process.

Anyone have any idea what could be causing this?

ValerieVonck · 2007-02-13, 12:20

Geoff,

I got similiar problems with my Amd 1 Ghz machine.
In the middle of a run (boinc rieselsieve) it restarted.
I looked into the event logs, and it indicated a problem with the ACPI (power supply ?? // mobo ??).
I ticked off: "restart on fault" ,but after a week, the machine didn't go further than the POST.

I concluded it was a fried mobo.
The main power connector to the mobo did show signs that the plastic did melt at one time.

Regards
Cedric

Offtopic: 500th post !

E_tron · 2007-02-20, 00:38

Not many motherboards go bad from the P3/early K7 era. try a new premium power supply, i think your current one is flaking.

It seems that the most common motherboard failure comes from bad capacitors, bad mofsets (ussually caused by a bad power supply), or something unrepairable.

Just to be safe, look at the capacitors on your motherboards. If they are oozing brown, green, and/or crusty stuff, then your capacitors have gone bad and need to be replaced. I don't know how to detect a bad mofset.

geoff · 2007-02-21, 05:11

Quote:

Originally Posted by E_tron

Just to be safe, look at the capacitors on your motherboards. If they are oozing brown, green, and/or crusty stuff, then your capacitors have gone bad and need to be replaced. I don't know how to detect a bad mofset.

The capacitors around the CPU socket look a little swollen, but none are oozing anything. I will try swapping the power supply. Thanks.

geoff · 2008-06-29, 01:56

This machine finally stopped working altogether. Afterward I found a partly burst capacitor hidden by the CPU heat sink, so I think that was most probably the cause.

2007-02-13, 04:28	#1
geoff Mar 2003 New Zealand 13×89 Posts	P3 reboots when CPU not under heavy load. I have a P3/800 that has developed a strange problem: If it is not running flat out, it reboots. I can boot using a mprime bootdisk and it runs the torture test without problems for hours, but when I stop the torture test it reboots within a few seconds. The machine is a HP vectra VL 400, it runs as a diskless client using the onboard LAN, has nothing but a floppy drive attached. It ran OK for about 4 months, but now reboots before getting through the network boot process. Anyone have any idea what could be causing this?

2007-02-13, 12:20	#2
ValerieVonck Mar 2004 Belgium 349₁₆ Posts	Geoff, I got similiar problems with my Amd 1 Ghz machine. In the middle of a run (boinc rieselsieve) it restarted. I looked into the event logs, and it indicated a problem with the ACPI (power supply ?? // mobo ??). I ticked off: "restart on fault" ,but after a week, the machine didn't go further than the POST. I concluded it was a fried mobo. The main power connector to the mobo did show signs that the plastic did melt at one time. Regards Cedric Offtopic: 500th post ! Last fiddled with by ValerieVonck on 2007-02-13 at 12:21

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2007-02-20, 00:38	#3
E_tron Sep 2002 Austin, TX 1061₈ Posts	Not many motherboards go bad from the P3/early K7 era. try a new premium power supply, i think your current one is flaking. It seems that the most common motherboard failure comes from bad capacitors, bad mofsets (ussually caused by a bad power supply), or something unrepairable. Just to be safe, look at the capacitors on your motherboards. If they are oozing brown, green, and/or crusty stuff, then your capacitors have gone bad and need to be replaced. I don't know how to detect a bad mofset.

2008-06-29, 01:56	#5
geoff Mar 2003 New Zealand 10010000101₂ Posts	This machine finally stopped working altogether. Afterward I found a partly burst capacitor hidden by the CPU heat sink, so I think that was most probably the cause.