I have a core 2 quad Q9550 - Gigabyte G31M ES2L motherboard - Kingston 2x2GB Ram - MSI n980 GT 1 GB video card - Zebronics Pro series 600W SMPS - 500+160 GB Seagate HD assembled from July 2009 with XP in 160GB and Ubuntu in 500GB. I use Ubuntu mainly for my day to day work. About one month back I updated the bios with the built in updater of the mother board. Everything was fine until yesterday. I logged in Ubuntu and the desktop came up and I went to the other room and when I came back the system was off! It didn't start again. I checked the SMPS but is working fine and narrowed the problem to the MOB. What can be the problem?
Only thing I know of at this point is the 'stripdown':
Mind you, there are two ways to do this: you can do it either in or out of the case. The advantages and drawbacks:in the case is easier and faster, but will not find case-related problems, like shorts from extra, mispositioned standoffs, or ground plane problems; out of the case takes longer, and you may run into 'reach' problems - power supply cables and front panel power switch headers may not be long enough; for the power supply, it's usually just a matter of removing four screws to temorarily relocate it; for the power switch, you can just do this (carefully):
You only need to short the pins momentarily - that's all the power switch does...Out of the case also affords you an easy opportunity to 'flip' the board to check your heatsink/fan attachment setup, to be sure all the pins are fully seated, locked, and not cracked... If you do the out of the case, you need to lay the board on a non-conductive surface: the box the MOBO came in is ideal; but - the foam pad it came with, and the bag it was in are not - being 'antistat', they are somewhat conductive, and may induce problems...
Another item worth mention at this point is case speakers: if you haven't got one - get one! http://www.cwc-group.com/casp.html
A lot of people operate under the misaprehension that the 'diagnostic beeps' should come through the speakers attached to their sound-card/chip - not so! Your three hundred dollar Altec-Lansings won't do you any good here - you have to have a case speaker attached to the front panel header, and, often by this point, it's the only diagnostic info you'll have to go on...
The standard 'strip-down':
Power down at PSU switch
CPU and heatsink/fan (check carefully that the fan retaining pins are fully inserted, completely locked, and not cracked)
one stick of RAM, in slot closest to CPU
video card and monitor connector (if more than one PCIe slot, again, in slot closest to CPU)
all power plugs - 20+4 or 24, 2x2 or 2x4 ATX power, graphics card power
case speaker and power switch connectors
keyboard (don't need a mouse at this point)
place jumper on RST_CMOS pins
remove jumper from RST_CMOS pins
power up at PSU switch
power up by depressing case power switch (or shorting the 'power' pins...)
If you get video, enter BIOS with <DEL> (may need a <TAB> to get to POST screen, if 'splash' screen is enabled)
Select and execute "Load Optimized Defaults" - save and exit, reboot
reinsert other components, one at a time, testing each time after addition...
Clear the CMOS by taking out the battery and reinstalling it or shorting the clr cmos headers on mobo. Load the default settings in bios on bootup and try starting the system in safe mode by repeatedly hitting F8 key during bootup. check the drivers signing status in your hardware information. reinstall drivers if problem found, else restart the system and u r good to go. This doesn't work then try running with minimal hardware and then go on adding till the system shows error and u will know the culprit.
Thanks for the replies. As I am not a technical person I took the safe route and took the MOBO to the gigabyte service centre and they diagnosed burnt power connection. But there was no provocation for the burning. Possibly circuit fault. Of course they didn't admit it but corrected the problem and gave it back saying that next time I will not be covered by warranty if I come with a burnt MOBO!