When I plug in the p4 connection, my power supply shuts down. At first, I thought the power supply went bad. Desktop computer MSI pm8pm-v with pentium D 840 775 was working fine, just quit like the power switch was turned off. I replaced the power supply with a new ultra, still won't power up. Without the p4 power connection plugged in, it will power up, power supply fan and cpu fan run, but no beeps no video. Plug in the p4 and both fans stop.
I think mb or cpu is bad. Which should I buy first?
plugging in p4 shuts off power supply 
Linear Mode
