When I first turn on my desktop it turns on fine. It will run for about 5 min. and then reboot. After it REBOOTS it will come up to the ASUS AI bios screen and hang there. I can hit the reset button and it does the same thing. The only way to power it off is if I cut off the power switch on the power supply. After I cut the switch on the power supply back on the LIGHTS on the fan and the power supply (both have led lights) come on but you can not power on the desktop when you push the power button. You have to wait until the lights go out and then it take about 10 min. before you can power it on. Is this a motherboard or a power supply problem? Thanks,It could be an overheating problem.

Is this a recent problem?

Try putting an external fan next to the computer and see if you can boot it.
Very recent. It started this past week. I'll try the fan idea. Thanks.Download Speedfan and post back with your temps.
http://www.download.com/SpeedFan/3000-2094_4-10067444.htmlUnable to do anything now. I power on the system and it powers itself off after about 5 seconds. After I try and power it on 3 or 4 times, you hold the power button in and it just clicks and the lights flash. Then it will not power on at all for about 5 minutes. See if you can borrow a power supply of equal or greater wattage. Hook it up in your MACHINE and see if it works. If it does not then we can rule that out as the culprit.I got a 550w power supply and hooked it up. Now when I power on the computer it powers itself off after about ten seconds. Check the heat sink & see if it is set properly?[ Re set if no] Also coulb be thermal paste has dried?You say fan [heat sink is running/}I had a similar sort of problem with rebooting and it turned out to be a dodgy MEMORY module!I too had a BAD memory module that caused the same problem. removed on card at a time & found it.....


Was an PIII gateway with 3 SDRAM slots
I have a new Power supply because I tested the other on and it failed. With the new PS it powers off after about ten seconds. I checked the memory and the heat sink - and added thermal paste. Nothing seems to work. I think my CPU is fried.