Cold boot problem - Motherboard or CPU?

robogoat

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Computer specs:

Gigabyte GA-P35-DS3 motherboard
Intel Q6600
512MB 8800GT
2 x 1GB Corsair 800Mhz DDR2 RAM
500GB WD HDD
Cooler Master Real Power 550W PSU

My story:
The problem I am experiencing with this computer occurred when, and only when, it has been turned off for at an hour or more. After I press the power button the computer seems to totally ignore me and will not turn on for a random amount of time. No fans start up, no LED's blink, no noise is made. Usually this would indicate a dead PSU or motherboard except when I accidentally left it turned on, about two hours later I returned to see it had started fine. That night I turned the computer off again and encountered the same problem! Basically, it's a 2 hour lag from hitting the power, and the computer turning on. I know the power supply is working because when a flash drive is plugged into a USB port, the LED inside will illuminate.

Now after I turned the computer off the other night it still hasn't started.

SUMMARY

When attempting a cold boot it takes anywhere between 30 minutes to 6 hours for the computer to start. During this time the only sign of life comes from my iPod being able charge when plugged into the USB port. Once the computer started everything ran fine, with the exception of the paused BIOS clock.

nVidia stress test and Micro-Scope diagnostics find no problems.



I have tried previously, and again since it's not turning on at all:

removing components and cleaning all terminals (nothing)

Replacing CMOS battery (nothing)

trying to cold boot with 1 stick of RAM (neither worked)

using another PSU (nothing)

using the current PSU in another computer (it worked perfectly)

booting outside of case to rule out shorts (nothing)

jumpering pins to rule out bad switch (nothing)

attempting cold boot with minimal components (nothing)

Is there anything else I can do to keep faultfinding? At risk of sounding stupid, I checked the CPU contact pins before and did not see any scratches or cracks etc and given it survived being worked at 100% usage for 2 hours and stayed below 60C with a stock cooler it's also prettymuch in the clear.

I have the opportunity to purchase a new motherboard this weekend and just wanted to see if I was correct in assuming motherboard is to blame (I'm 99% sure) before spending more money.

Let me know if you need more information. All help and advice is greatly appreciated!
 

Cache

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Definitely a strange issue!

You're right, unfortunately, when you've eliminated all the other possibilities, all you have left is the motherboard as the culprit. Good luck!
 
That pretty much narrows it down to a faulty board. You can try taking all of you components and running them on another board to rule out everything else. Did anything out of the ordinary happen when this started? Was it a gradually getting worse or sporadic when it first started happening?
 

robogoat

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Good news! I managed to borrow a friend's PC and can verify RAM and graphics card are good! Unfortunately his board is a bit old and I couldn't test out my CPU (which is what I wanted to test the most!! lol)

Yeah, it first started happening when the board was about 3 months old and only and the lag from hitting the power to booting took about 30 seconds or so, and I just assumed it was a little quirk of the board and recently it jumped from 30 seconds to around anywhere between 2 - 6 hours to start! Now it simply refuses to do anything at all.

Heh, this is my first homebuild so I guess I've just had a bit of bad luck so far. I was reluctant to claim warranty at first in fear I'd just plugged the power in wrong or something. What put me off the most was when it finally stated and ran perfectly. Have any of you guys seen anything like this, or do I have a "special" motherboard?
 

Cache

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I had an old (like... used by the ancient Egyptians as part of a religious ceremony commemorating the creation of the first pyramid) Asus board that had a bad capacitor that would his now and then. Sounded like a spitting cobra, it was the damnedest thing because once I heard it, I had about 20 seconds before the whole PC just shutdown. Took me forever to track it down, but.... well, all good things come to an end. Then I moved up to a mighty PIII chip.

Good times. Good times. I think it's just a bad board, these things happen. The hair you pulled out will grow back and hopefully by then you'll have the new board installed.
 
The only similar thing I've seen, is a computer booting off a SATA HDD with the drive plugged into a SATA adapter card. It was extremely slow booting, but not that slow. You have ruled out everything but the board and cpu. My money is on the board.

HAPPY SHOPPING
 

IH8U

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Another would be to disconnect the case power switch, and attempt to "Jump" the pins using a flat screwdriver. This will rule out the power switch being bad. Sometimes case manufacturers go cheap with the switches, and if it turns out to be the problem, go to: http://www.frozencpu.com/
they should have new switches to replace the bad one.
 


To test this, just swap the power and reset switches. The odds of both being bad are pretty small.
 

robogoat

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I've tried that too, but to no avail. Back when it started after a while I tried shorting the two power switch pins for about half a second and two hours later it booted back into life without me touching anything (after the pins).

I was wondering, can any other components (other than the motherboard) effect the BIOS clock like making it stop after the power is removed? The BIOS clock problem occurs only when the computer is turned off, even when the PSU is switched off and the power cord is removed.
 

bonanzaguy

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Seeing as how no fans or anything start up and you have tested a wide range of parts, I have a really hard time believing it is anything other than the motherboard.
 

robogoat

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Excellent! That makes me feel more confident.

My new motherboard should be ready to pick up Monday. I'll keep you posted on any further progress!
 

robogoat

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Success! Haha sorry about the heavily delayed response, after a spate of irritating mistakes being made by suppliers I have finally got my new motherboard today!! :D

Everything seems to be in working order, booted perfectly first time and hasn't skipped a beat as of yet. I guess the real test will be tomorrow morning to see whether it will cold boot okay again.

Thanks for all the help guys! I really appreciate it.