My computer was working normally yesterday, but today the monitor turns black even though the PC itself stays powered on. When I switch the monitor off and back on, the desktop appears briefly and then disappears again. The HDMI cable is connected securely, and I also tested a VGA cable with the same result. I'm not very experienced with troubleshooting PCs. How can I tell whether the monitor or the computer is causing the problem?
1 Answer
Since the desktop appears for a moment and then vanishes with both HDMI and VGA, the monitor is the more likely culprit. When it goes black, shine a phone flashlight closely at the panel. If you can faintly see the desktop, the monitor’s backlight may be failing. Also press the monitor’s built-in menu button after the screen goes black. If the menu is visible, the monitor is still producing an image and the problem could be the PC’s video output or input selection. If the menu also disappears, the monitor itself probably needs repair or replacement. The best confirmation would be connecting the computer to a TV or another monitor.
I don’t have another monitor available to test. I tried the flashlight, but I couldn’t see anything—the screen looked completely off. The monitor menu also wouldn’t appear while the HDMI cable was connected, although it stayed visible after I unplugged the cable until the monitor eventually went into standby.