Bit of history here, last year bought a Gigabyte board (model fails me) - ran well for 12 months but we had a power outage and even though the pc was off at the time, when I tried to restart the machine, the fans would spin for a second or two and then shut down. Cleared CMOS, took off all components, changed graphics card etc, all to no joy. Anyway, took the mobo etc out and bought the GA-7N400 and Athlon 2800. Put them in and all worked fine until today. In the meantime, put old motherboard and chip in another case, and they worked fine!!!! Anyway, today, the PC was off but the switch on the back of the machine was on the ON position. Another power outage in the district and again although the machine was OFF, the switch on the back of the machine was on the ON position. Again, today after power restored, the machine that was working perfectly well for 6 months, now switches off a second or two after the fans spin. There is an audible TICK when the machine shuts down. Again, cleared CMOS with no joy, changed graphics cards, took off peripherals etc with the same result. PLEASE PLEASE PLEASE tell me what's going on here? Gigabyte technical support, as usual, as useful as a chocolate sunshade.

Perhaps it's a PSU problem. If the mobo worked in one case and not the other, and the new mobo doesn't work right in the old case, then chances are your PSU is busted from the power outage. AMD Athlon XP 1800+ Geforce 3 512MB DDR266 RAM 250W PSU 56X CD-ROM 52x24x52 Samsung CD-RW 20 GB Maxtor HDD 80 GB Hitachi HDD Gigabyte GA-7DX+ MOBO SMC 10/100 LAN

livingdecay's analysis sounds perfectly logical to me.

out of curiosity, was your PSU plugged into an outlet/power strip with surge protection? and what does your PSU have in the way of overvoltage and overload protection? If you end up replacing the PSU, make sure you get a quality one, because a power outtage, or even a power surge, shouldn't fry your PSU every time.

the psu was connected to a surge protector. Funnily enough going to try changing the psu later on today so will let everybody know how it goes. What i'm annoyed about is a power outage with the pc off can cause SOME damage.

There is off and then there is OFF. Most new computer power supplies are off. They use electronuc switching to turn on and off. So the computer is off but the power supply is always on. Some power supplies have a switch on the back, these will turn OFF, but you lose the convenience of push button startup. Some people use the switch on their surge protector, then press the button. Even if you use the switch on the surge protector, a sustained surge greater than 6000 volts will get through. That is why it is recommended that you pull the plug and disconnect phone and cable lines during a storm. 6000 volts is what regular house wiring is supposed withstand, the back switch on the power supply and the rest of the components will not.