CPU Turning itself off/overclocking error

[slickstick]

Hey guys I've built a few rigs in the past and never had any problems until now. This comp will shut itself off during various phases of startup... either before windows boots or sometimes after the desktop is mostly loaded already. Sometimes I also get an "overclocking error" but when I check bios it all seems to be on auto/standard so I'm not sure why it believes to be overclocking.

My guess is overheating but the heatsink seems on good and I used thermal paste so I don't know... tried with case side open and fan blowing on as well. Temp gauges read low 30sF so seems normal.

This is an Intel Pentium D 805+ and Asus P5LD2 Mobo. Thanks for tips fellas.

 

[amdskip]

What power supply are you using?

 

[slickstick]

amdskip - P/S came with Aspire XNavigator case:

Power Supply ATX 500W dual fan w/ automatic fan speed control. Connector 20 + 4 pin

Thanks for the help boss.

 

[slickstick]

getting a single beep at startup - Asus Mobo guide says this means "keyboard controller error, refresh time error, no master drive detected"

Tried running memtest and it shut itself off in the middle.

Booted up with a single stick of memory and each stick would have the same problem so it doesn't appear to be the memory.

 

[slickstick]

I've also tried booting up without the keyboard because of the "keyboard controller error" and someone swears that has been known to cause problems. No luck, any suggestions?

 

[OCedHrt]

Make sure the MB isn't shorted to the case. More specifically, try booting up without the MB installed in the case.

It could be a faulty PSU as well.

 

[lyssword]

set cpu voltage manually, to where its suppose to be @ stock