Computer turns off, then won't Post or Boot for at least 30min, then is fine for another 24hrs

[caenus]

I started another thread in Tech Support area, but wasn't getting much help. Once the computer turned itself off, we could get into the BIOS but then it would shut off. We tried a different power supply and same thing happened. We tried a different power supply and are thinking the motherboard may have gone bad. If thats possible?

Please click below to see the other thread with details on the problem

Thread

 

[MoFunk]

Have you ruled out the power switch? I had a problem with a clients PC where it would do just that. Turned out to be a short in the power switch. To test, do this. Find the posts on the motherboard where the power switch and the HD led's and stuff go into. Now take off the power switch line. the with a flat head screw driver touch it to the 2 posts where the power line was once plugged into. This should get the computer to start. Let it run for a few days. If it does, then you have a bad power switch, if it still turns off, you may have a shorting issue with the motherboard.

 

[Amber]

I had a power supply do the same thing,some times it was ok for a week then no good try switching with a dirffant one

 

[caenus]

I did try switching to a different power supply when I couldn't get the computer started again. With the new power supply I wasn't able to get the computer started.

I'll give that power switch thing a try tomorrow.

 

[clumsum]

Try wiggling all the case (switch, led, re-set) wiring around and see what happens ................. ?

My re-set switch was shorting out to the case on a pc recently ............. you have to check everything, and be as patient as possible!

good luck ...........

 

[Davbaron]

Caenus - Another possibility is what i experienced. My 'puter went off in full flight and wouldn't re boot. No Beeps - nothing. Changed PSU and was Ok for a few days then same thing. Took puter to bits and re located everything but no change.
Thought that either the new PSU had gone Kaput or the mobo had. Then a stroke of luck.
I broke the HSF clip ! and so had to buy a new HSF. I scrpaed the metal tab on top of processor and re fitted the HSF and --BINGO - all started and is OK.
I had been overheating and the Processor metal plate had got crusted over and then the mobo or PSU sensed it and wouldn't start the puter. I had had a 235 w PSU ( now a 350) and a memory stick wasn't right _ Check your memory with Norton Utilities- I had a fault and didn't know it. The offending stick is now out and I'm running better on 256 than I was on 512.
I nearly blamed the mobo !! Saved some money there, boyo

 

[caenus]

I will try a different heatsink, I've got a few laying around, but it has been doing its job for many months. Also, we replaced the RAM that was in there, in case that was the problem. Also, its not that once the computer dies it won't be able to reboot for 30min or so. After that time it boots normally as if there was no problem.

Also, these problems happened all of a sudden, no new installation of hardware or anything inside was touched in the last 4 months.

 

[ronach]

The 30 min time frame before running again is the key. Check everything for overheating, next time it shutsdown, put one hand on the chassis for grounding, then physically touch everything else, units, components ect. Your fingertip will find an overheated component or H/D unit. If you are unsure how hot things normally run, then do a dry run and shutdown when the sys is running ok, then do the temp sense with the finger thing. Good luck. ronach