pc only posts after warm boot.

[stumped111]

Can anyone tell me the boot up sequence of the motherboard?
The pc will not boot from cold -blank screen - not beeps but fans working. It will eventually boot up if I leave power on and hit reset button 8 or so times after waiting for around 5 minuted (warm boot).

The motherboard will power down on with the blank screen when the power button held in for 4 secs.

I have tried changing to backup bios resetting bios,new battery (old obne was fine)but no difference.
I have stripped down to m/b (gigabyte ga7-vrxp rev 1), xp2000 cpu, 2 memory cards and hercules g force2 mmx in agp slot.
I have used 1 memory card at a time, bought a new 550w power supply (old one was fine)but still no boot. I also have 2 fans inside case.

The only mistake I made when building pc was to assume fan to cpu heatsink(silvermountain) was the right way around- WRONG). I only noticed this after 8 months when pc started to go.

I did overclock slightly from 133fsb to 141 fsb but cpu temp wouldn't have went close to 58c - even with the cpu fan the wring way around).

I intend to strip down to m/b and add 1 component at a time. Do I start with cpu, memory or video card.

thanks for reading.

stumped..

[ski]

Borrow a different known working video card and memory.

If that's not possible, then remove the video card and memroy.
If there are no beeps, then either the CPU or MB may be bad.

[mjc]

Of it woll boot after a period of "warming up" then try disableing the "Quickpost"/quick boot options in the BIOS.

[stumped111]

I'll try m/b without video card or memory and hope for beeps.

The bios doesn't have a quick boot up option enable/disable.

I remember reading something about a warm boot up misses out some of the initial post checks which is perhaps why it boots up at all.

Once it boots up the pc is fine - runs perfect.

I will let you know what happens if my pc continues to let me boot up.

thanks.

[Budfred]

To do a minimal boot, you need the mobo, CPU, video, keyboard, power, and one stick RAM. If it won't post with that, you will have to test out each of those components in a known good setup.

Edit:

The warm boot also often involves the hard drive already moving so it doesn't take as long to spin up. The hard drive spinning up too slow can prevent a boot. You disable the quick boot to give it more time. You might want to check BIOS settings again, it may not have the same name, but there is probably some sort of quick POST setting that you can change.

[stumped111]

I stripped pc down further to m/b and cpu. nothing else
-no mouse,keyboard,memory,graphics card etc connected.

M/b gave 3 short beeps then a gap of about 1 second and 3 short again.

When I added either of the 2 memory cards or video card silence.

I presume it is now down to cpu or m/b.

When I built back up again the cmos sum error came up so I reset and entered defaults then failsafe.

I have rechecked bios for quickboot but not there. Anyway, as it freezes before post is completed,even without peripherals I think it is down to m/b and cpu.

Any ideas apart from leaving with shop who will check it out for £20.

[Budfred]

If you are getting beeps with only the mobo and CPU, it probably means that they are ok and the BIOS is trying to tell you that you don't have memory or video. If the mobo or CPU was bad, you wouldn't get anything. This suggests that your RAM or your video is causing the problem and the RAM is a more likely culprit. Another possibility is that your power supply is bad and that you don't have enough power to do anything when more than the mobo and CPU is hooked up. It may even be a short that you somehow activate when you install the RAM or video. But again, the mobo and CPU are probably least likely to be it...