I Have fitted a new motherboard (MSI K9AGM2) toegether with an AMD Sempron cpu and 1 gig ram purchased as a package. The unit booted up but while I was in setup keying in date and time everything shutdown (unit ran for 5 mnutes). Now when I try to start it goes for 1 to 2 seconds then everything shuts down including fan on power supply. If i unplug the Jpw1 (power for cpu) it keeps running ok and doesn't switch off without the cpu. Heat sink checked and reset - doesn't seem to be hot and couldn't in 1 second. Have unpluged power to hard drive and cd but that doesn't change it. Must be something switching everything off at startup. Any idea's??