Hi cughe,

I'm going to move your message to the Alienware forum for more help.

cughe,

* Switch the monitor and PC off
* Unplug the power cord from the back of the PC
* Disconnect the monitor from the video card
* Remove the leftside panel
* Lay the computer down on its right side
* Disconnect and reconnect all plugs, cables, and memory sticks (The memory sticks should click when fully inserted)
* Remove and reseat the video card, sound card, NIC, etc. in the motherboard slots
* Close the leftside panel
* Stand the PC up
* Reconnect the monitor to the video card
* Reconnect the PC power cord
* Power on the monitor and then the PC. Any difference in the issue?

1st thing thks to Osprey who moved my post here for more help...and thks Chris for help...i did exactly as advice and found 1 of the 2 power connector to video card was not plugged in completely,after that computer turned on and ran longer than usually...it's still running for testing....will update any problem when found,thks again.

hi Christ,seems computer got an intermittent problem,if i leave computer 2,3 days in a corner then it runs for few hours then shut down itself again and can not start it back ..when it shut down suddenly i touched radiator and power supply and felt like cold not even warm...might have mother board or cpu problem please help.tang.

psu is the cause.