I was called by a customer this morning about a computer that had "gone to sleep and wouldn't wake up."
The symptom was that when the WIndows login screen appeared the screen went black and wouldn't come back on. Only a reboot would bring it back up, and again only for a couple of seconds. They had tried a different monitor with the same results. When I arrive at the customer's, I found that the screen had a "no signal" message on the screen which was not surprising since there had been no activity for an hour. Using my laptop, I VNC'd into the computer got full video. On the computer's monitor, the "no signal" message went away, but the screen remained blank. Other than the video, the computer is fully operational, and can be controlled via the VNC session.
The problem appears to be hardware related. Here are the tests that I tried:
In Windows - changed the video mode via VNC. Each time the mode changed, the monitor would display for about two seconds then blank.
In POST - Banner displays for two seconds, then blanks
- Boot summary displays for two seconds, then blanks
In Windows - "Starting Windows" screen displays for two seconds, then blanks
In Windows - "Select user" screen displays for two seconds, then blanks
The monitor never shows "no signal" until there has been ample time of inactivity to go into sleep mode. So, the monitor must be recognizing some type of signal.
Motherboard - Gigabyte G31M-ES2L
Memory - 2 GB
Monitor - Acer AL1914
OS - Windows 7 - 32 bit
Any and all words of wisdom or adult supervision will be appreciated.