nac
Aspiring Novelist
It did work in your place at first, right? And it worked intermittently, right? If you're doubtful about your cable and if you're again taking it to him, then take everything including cable, wire, connectors, HDMI/VGA cable everything you use in your place except monitor (that would be too many). If it's CPU, I don't think it will work intermittently. Since you've already ruled out PSU, it should be either motherboard (highly likely) or RAM. If you've debug speaker installed, you could hear the beep code when you don't install RAM.