repeated problem with CPU

[Easton College]

i wondered if anyone would have a suggestion for what might be causing the following problem...

i have a motherboard (ASUS A7V8X-X), and a CPU (ATHLON XP2200 266FSB). the CPU works fine for about 5 hours, then i get repeated lock ups in windows after about 5 minutes of use. sometimes the PC fails to POST, or if it does it goes straight into the settings and tells me that the CPU speed settings were incorrect on the previous boot. i press the arrow keys and the PC freezes.

i figured this was probably a CPU fault so i sent it back and got a replacement. same thing happened. so i sent it back again. and the same thing happened again with the replacement. so i figured it was the motherboard. sent it back, got a replacement, same thing happened again. i have tested the RAM with memtest86, it checks out as OK. just in case, i replaced the original PSU with this
but it hasn't really made a difference.

so i have decided i'll return the motherboard and CPU and get different types of both. maybe something just isn't compatible somewhere else in my machine, i have no idea what.

but does anyone have any idea at all as to what might be causing this? is the CPU just blowing up after a bit of use, and if so what would cause that to happen?

thanks!

[gazzak]

First thought is heat. Would explain why the PC works OK for a while then starts misbehaving. Check the fan on the heatsink is blowing fan AT the heatsink rather than away from it. Check it's seated correctly, (though to mis-seat the heatsink 3 times would be unfortunate ). Run the PC with the case open and maybe a fan blowing in there to see if it runs stable. Get an application for monitoring the CPU temperature, ASUS will have one. If you're overclocking then put the settings back to default. Keep us informed of progress!

[Easton College]

First thought is heat. Would explain why the PC works OK for a while then starts misbehaving. Check the fan on the heatsink is blowing fan AT the heatsink rather than away from it. Check it's seated correctly, (though to mis-seat the heatsink 3 times would be unfortunate ). Run the PC with the case open and maybe a fan blowing in there to see if it runs stable. Get an application for monitoring the CPU temperature, ASUS will have one. If you're overclocking then put the settings back to default. Keep us informed of progress!

thanks for the suggestions, that was something else that had crossed my mind but i forgot to mention it! i've tired the ASUS probe software and the temperatures are certainly not troublesome at all. the heatsink came pre-attached to the fan so unless the manufacturer screwed up, that shouldn't be the problem

no overclocking here either, everything is at default.

something i didn't explain very clearly:

the CPU works fine for the first three to five hours of it's lifetime. then it starts locking up after 5 minutes each time i boot up. i could leave the PC off for a week, then turn it on and it'll lockup almost straight away.

[Matridom]

I would recommend getting motherboard monitor and track all the temps and all the voltages, With lock up's like that, i would suspect cpu ram or motherboard.

[Easton College]

voltage is something i haven't really thought about - what ought i be looking for there? it's not something i really have much knowledge on.

i am certain it is CPU or motherboard, but i am puzzled as to why it has happened with 3 different CPU's.

[gazzak]

The Asus Probe software you have will monitor the voltages too. Watch them for spikes.

[Easton College]

ok, the PC won't stay running long enough to get ASUS probe installed. but i was able to get these stats from an option before bootup:

V Core : 1.57
+3.3V : 3.31
+5V : 4.99
+12V : 12.03

MB temp: 26 deg C / 78.5 deg F
CPU temp: 29 deg C / 84 deg F

anything out of the ordinary there? i didn't notice any changes in these numbers. then the computer froze again

[ADisturbance]

Since you've already replaced the mobo and cpu and are still experiencing the same issue. I would suspect mem or expansion cards. Remove everything except for the vid card and 1 stick of memory. If you can get into the bios and remain there for a longer than it was taking to lock the system previously I would reinsert mem 1 stick at a time and repeat test. If system remains functional at that time slowly add back each other piece of hardware until the issue recurs. Then you will know where the problem is.

[Easton College]

thanks for the suggestion. i've tried the memory one, so will have a go with removing the cards (the only ones being modem and a USB expansion card).

[Easton College]

ADisturbance, i do believe you've cracked it! took out the modem, PC boots fine. stuck it back in again, no POST. how crazy! went and bought a new modem at the local store, PC has been running without a hitch for the past 5 hours. i had no idea that a faulty modem could cause so much bother, i have been messing around with the CPU and motherboard for a couple of months now and it appears to be a lousy expansion card. ack!!! at least i know this for the future now. many thanks.