I shipped a new computer to a friend a few weeks ago. I can't begin to tell about the nightmares the shipping caused us, but we've seemed to work out all of those kinks and resolved any issues he was having...until now.
He tells me that when he boots the computer, his monitor doesn't always become active. Instead, it sometimes will stay at a yellow light and the screen will read "No Signal". He tried turning the monitor on and off but that didn't help. The only way he can get it to work is by unplugging the DVI cable from the back of the PC and re-attaching it.
Keep in mind, however, that this doesn't always happen. There are times when the computer boots and the monitor somes on. For now, it seems to be happening at random.
I know the PC is booting because when he unpluggs the monitor cable and re-attaches it, he's sitting on his desktop. And I doubt, although it's possible, that there is anything wrong with his monitor because it's relatively new (few months old) and he never had trouble with it on his old computer.
Any ideas on how I should go about diagnosing this problem?
I'll have to find out what the monitor is, but I know the OS is Vista Ultimate and the video card is the new ATI 4870 X2 (by HMI I think).