Odd problem with my PC during cold boots.

[Spiderkeys]

I've got this strange problem with multi-boot PC, a which used to be my most reliable trustworthy machine, and after any ideas, one day during a cold boot a few months back, it blue screened on me, just after a few minutes starting Windows, I hit reset, no display, no disk activity, so hit power/on off, yet no signs of life, just fans and power light.

My Motherboard is a P5G41-M LX, trying to get down to the problem, I just about stripped the componments, hard drives, video cards, and unnessary cables, to just about naked state, then I eventually got to the RAM, swapped my 2 (2GIGs sticks) around, a few times, and then tested it with 1 stick, and eventually it came back to life and booted, and after it warmed up, I could power off, put the other stick in, and everything is good again.

So all I know the fact is, it's works perfectly when warm, terrible when cold, every morning it's a mission to get it start (Stabilize), usually a bsod a few minutes into Windows, then no display nothing, unless I power down, take both sticks out, and insert one back in, wait till it's warm then power down a put the other one in.

Things I've already tested so far -

1. Memtests when it's in warm working condition so I get a display, is been all good there.
2. Changed Power Supply to a brand new one.
3. Removed Video Card, tested it with onboard video, nothing there, (like no display if cold)
4. Since my motherboard is a combo DDR3 and DDR2 RAM, I took out all DDR3, and testing known working DDR2 RAM from my other PC, yet no signs of life.
5. Tweaked the RAM Voltages in BIOS from like default 1.5v to about 1.56v
6. Flashed BIOS last night from version, 5.03 to 7.02, but still same issue when I attempted to boot from cold this morning.

More frustating, is my motherboard speaker doesn't appear to be working, because beeps could help me a lot, I tried two motherboard speakers connectors so far, and yet silence.

I presumed, I must have bad DIMM Slots, but even can't get DDR2 RAM, to work either in those slots/

But to get a long story straight, horrible unreliable operation when cold, excellent operation when warm.

The only thing I haven't touched yet is the CPU, yet is so odd's why it's so difficult and a lot of work inside the case just to get it to start.

These days it's like
1. Power up, let it load windows then let it BSOD and crash and cut all display. (3-4mins)
2. Power-down, remove cover then remove both RAM Sticks, swap them around but just put one of the Sticks back in.
3. Power-up let it load Windows again and let it sit for half an hour to warm quite a bit ( I sometimes run a game or put it through a stress-test to hurry things up a bit)
4. Power-down, put the 2nd stick of RAM back in so it's got 4gig again, replace cover.
5. Turn on, and your as good to go, again for the rest of the day at least

Then course the cycle starts again tommorow after a good night power-down, and it becomes cold again.

Just miss it no longer being able to start and be ready when just a press of the button as it used to be.

 

[popatim]

Seems like you've narrowed it down to the motherbd to me.
Question: When its warmed up and ready to work, do you get the single beep to indicate a successful POST then ?

 

[Spiderkeys]

Another Problem, there's never been a PC Speaker connected to it since it was given to me, so I got hold a couple of 4-pin connectors elsewhere, attached it the PC Speaker connector, still silence, then tried another, so I presume this used PC speaker never did work in the first place, but yet, I do wish I could hear the beeps it might help me a lot, fact is if it doesn't blue screen on me within 20 minutes of boot time, I can fully trust it again for the rest of the day.