Troubleshoot Monitor Issues by Swapping Hardware
Because the PC’s video system contains two parts, you have to check two hardware items when you are troubleshooting: the monitor and the display adapter. To do forensic troubleshooting, it helps to swap out the parts to determine specifically where the trouble lies.
Obviously, you cannot swap out a monitor and a display adapter unless you have spares lounging about. But when you have a spare monitor or display adapter, you can use them to help troubleshoot.
Start with the monitor:
Turn off the computer and monitor.
Unplug the monitor and disconnect it from the console.
Attach the replacement monitor.
Turn on the computer.
Assuming that you know the replacement monitor works, the computer should display an image on the screen. If not, the problem lies with the display adapter.
You can use similar steps to troubleshoot a display adapter. Replace the current adapter with one that you know works. If this trick fixes the problem, you know that you need to buy a new display adapter.
The replacements you use for swapping must be working in order for the swap to be an effective troubleshooting tool.
This trick still works when the display adapter is part of the motherboard: Simply plug a video adapter into one of the PC’s expansion slots. If it works, the problem is in the video circuitry on the motherboard. Buy a new display adapter.