AN8 Ultra strange error codes

I have an AN8 Ultra that I have been using for a year no problems. Last night it wouldn't stay off so I switched the power supply switch off. This morning when I try to boot it up it won't. When I first turn the power supply on it would go fine and get to "01". After hitting the power button though it would go to "03" then to "F ". I leave the second digit empty because it doesn't show anything. I've cleared the cmos and now when I power it up it got to " 3" then sits on "F ". After a while it gets to "01" when I hit the power button it begins cycling through "F " and " 3". Every time it is on "F " the power light flashes and the CPU fun budges but then they both stop when it hits " 3" again, which is almost instantly. Any ideas what the problem is?

Here are the specs:
MB: Abit AN8 Ultra
CPU: AMD Athlon 64 X2 3800+
Memory: 2x1 Gig GeIL Value
Graphics: XFX Geforce 7800GT
Power: COOLMAX CX-550B ATX v2.01 550W Power Supply
Sound: Creative Sound Blaster X-Fi XtremeMusic (Though it is currently unplugged.)

got a spare PSU to try?

I don't have a spare PSU. However some things have changed. After sitting there for a while it finally booted. When I rebooted again it got stuck with post code 90 which the manual says is uGuru has finished and is turning things over to Award. I rebooted again and now it gets stuck on CF the code meaning that it is testing the R/W functionality of the cmos. It is just really strange. I suppose it could be the PSU but it doesn't seem like it.

CF is often caused by leaving the clearCMOS jumper in "clear" rather than "run" so I would check your jumper.

I still suspect your PSU though ...
What is it, that code is for a 120mm fan? :P

:Oops: yeah that was for a fan. I grabbed th wrong line out of my order history. Anyway I fixed it now. It is a COOLMAX CX-550B ATX v2.01 550W Power Supply.

Well it looks like this particular power supply starts to have problems after a year so I am going to replace it and see what happens. I'll post the results.

That was it. I replaced the power supply with a 650W BFG and everything works great. You were right about the CF code being because the cmos jumper was not on right as well. Thanks for you help BUFF.

glad that you are sorted :)