Gigabyte 8IRXP start itself!!!!

[LinPack]

Hi mates

My computer with a P4 1.6Ghz and GA 8IRXP mainboard suddenly died. When I plug the power cord in, it starts itself.

I removed all the expansion card, ram, even CPU, the mainboard keeps start itself again everytime i plug it into main. But it not boot, here's the symtoms:

1. Power on every time plug power on.
2. Not boot, no POST, no beeep, no video, justpower on.
3. All the power rails are ok, measured by VOM multimeter
4. VCore OK, 1.5 volt, measured at the VSEN of Intersil HIP 6302 VRM controller.
5. CPU not warmer when power on
7. When i remove the CPU, VCore no longer available, return to 0 Volt (Is it normal?)
8. It's a dual bios board, so dead bios is rare
9. All caps are visually checked OK, but i haven't replaced. Measured caps onboard, there's no short circuit, but dont know if caps are leaked

What i have done:
1. Replace the CPU
2. Replace PSU
3. Replace RAM
4. Remove and repalce everything else
5. Clear CMOS 1001 times

Still no lucks.

Please advise me what to do next, should i re-caps all or should i do some more check? I really dont know what to check next.

And the 2 bios chips are soldered, too bad!

[Tom41]

Many boards do have an option to restart automatically after a power outage - when the mains is re-applied, the system starts up without you having to press the Power button.

Does it power off if you press and hold the Power button on the front? Check if the Reset switch (if applicable) is jammed in or connected the wrong way round. Also try a different video card - many boards refuse to boot if no video card is inserted, and the video card itself may be dead.

What make are the caps? Some brands such as Teapo tend to fail without any physical signs - to be sure you'd need to desolder the caps and check with an ESR meter.

[LinPack]

No, the power switch has no effect. I've tripped everything out, even the CPU was detached. It's just the mainboard only and it power on itself, even without the CPU.

As I said, I've changed the whole system and it's the mainboard fault, 99.99% definitely.

I think i should re-cap it.

But i want to listen to your advise before i do that.

[Rainbow]

Does the CPU, chipset and clock generator chip get warm? If not, then it might be a bad crystal.