Mobo wont boot

[darob112]

My computer has been running excellent for a while now, but when I came home from work today, I turned my pc on by the fron power button and it starts up for about 3 seconds, beeps once then completely shuts down again. I have to turn to power supply off then unplug the supply, reverse the process then try again. same thing happens.

ABIT UL8 uli m1689
1.5gb RAM
3200+ amd
ati radeon x1650

 

[kimsland]

Have a look here: Tutorial: No POST (Power On Self Test

 

[darob112]

Still wont work, reseated everything, unplugged everything then plugged it back in. CMOS reset. lol