Aggrevating Boot Issue

[Venner]

I've been building and troubleshooting PCs since the early 90s, but I'm having an issue with my father's PC that I'm having a heck of a time isolating. I put the machine together for him back in November, and he's had no issues until this week.

After the machine sits overnight, it won't boot. It won't even POST. The LEDs on the motherboard come on, so power is getting to the board and when I hit the power button, the CPU fan spins once or twice and then stops. I've tried removing and/or reseating every blasted chip / card / connector on the board, checking for shorts, etc, and it makes no difference. I finally found that if I short the "clear CMOS" pins four or five times in a row, it eventually springs back to life and boots.

At that point, I can shut down the machine and it will warm or cold boot fine. My thoughts are obviously that it is a problem with the motherboard or PSU. I've checked all the caps and they all seem fine. I've replaced the battery. I've re-flashed several different BIOSes without problem (speculating that BIOS was corrupted). I've even tried unplugging it and letting it sit a couple of hours (also with the battery pulled) and it starts up fine when I plug it back in and hit power.

However, *every day this week* when my father tries to start up the machine 12+ hours later, it again refuses to POST, and I go over and reset the CMOS, go through all the motions, etc. I'm pulling my hair out.

If anyone has any ideas, I would be most appreciative! My next step will be to buy a replacement motherboard, which is a significant outlay of expense.


System
Motherboard: GA-Z68X-UD3H-B3 Rev. 1 Socket 1155 (Tried both the U1L UEFI bios, as well as reverting to the Award F11/F12 bios)
CPU: Intel i5-2500K (stock speed)
Video: Intel HD3000 (Integrated video on 2500K cpu)
Ram: 8Gb Corsair DDR3 (4Gbx2) (Passed mem tests just fine)

 

[BonzaiDuck]

I've been building and troubleshooting PCs since the early 90s, but I'm having an issue with my father's PC that I'm having a heck of a time isolating. I put the machine together for him back in November, and he's had no issues until this week.

After the machine sits overnight, it won't boot. It won't even POST. The LEDs on the motherboard come on, so power is getting to the board and when I hit the power button, the CPU fan spins once or twice and then stops. I've tried removing and/or reseating every blasted chip / card / connector on the board, checking for shorts, etc, and it makes no difference. I finally found that if I short the "clear CMOS" pins four or five times in a row, it eventually springs back to life and boots.

At that point, I can shut down the machine and it will warm or cold boot fine. My thoughts are obviously that it is a problem with the motherboard or PSU. I've checked all the caps and they all seem fine. I've replaced the battery. I've re-flashed several different BIOSes without problem (speculating that BIOS was corrupted). I've even tried unplugging it and letting it sit a couple of hours (also with the battery pulled) and it starts up fine when I plug it back in and hit power.

However, *every day this week* when my father tries to start up the machine 12+ hours later, it again refuses to POST, and I go over and reset the CMOS, go through all the motions, etc. I'm pulling my hair out.

If anyone has any ideas, I would be most appreciative! My next step will be to buy a replacement motherboard, which is a significant outlay of expense.


System
Motherboard: GA-Z68X-UD3H-B3 Rev. 1 Socket 1155 (Tried both the U1L UEFI bios, as well as reverting to the Award F11/F12 bios)
CPU: Intel i5-2500K (stock speed)
Video: Intel HD3000 (Integrated video on 2500K cpu)
Ram: 8Gb Corsair DDR3 (4Gbx2) (Passed mem tests just fine)

If you don't already have a hand-held $20 PSU tester, I'd suggest getting one -- "building and troubleshooting since the early 90s."

It sound like that COULD be your problem; it could still be the mobo. You need to find out which it is. It happened to me last year -- for a Seasonic unit, no less, but it was 7 years old, and stressed continually by leaving it in a sleep-state for days as opposed to scheduled hibernation.

Just as a footnote, sleep can put a strain on a PSU if it's allowed to remain that way for days at a time. No cooling, ya see . . . So the best approach is to let the system sleep for an hour or two, and set it up to hibernate at then end of that period.

 

[john3850]

On my last c2d build I had a bad CMOS that would boot up normal for a few hours after you reset the bios then would not restart.
After changing 2 batteries the ps and memory I gave up.

 

[bigboxes]

What BD said. I've been doing the same thing since the late 90's. Those symptoms make me suspect the mobo. First, I would test the psu and also swap out with a known working power supply to see if the issues go away. If it is the mobo it's only been 9 months so RMA if necessary.

 

[Eelectricity]

Having just gone through a bad PSU that would be my guess. I would replace the PSU first because unless you already have a good one it will be an upgrade anyway. If you replace the MB and you still have problems you now have an extra MB. I guess you could ship it back. Maybe order both at the same time.

Or get replacements if under warranty, can sometimes take forever though.

 

[PhIlLy ChEeSe]

Been building since the 90's and you never learned to swap out parts? your a victim of your own teachings.

 

[Puffnstuff]

A bad ps is my first inclination based upon the mentioned behavior. The fact that it will eventually post tells me that the power source is the problem and I've seen it before when the cold boot inrush current exceeds a ps's capacity to deliver during boot.