monitor turns off but computer still running

If the other monitor brings up the display back then the problem was in the previous monitor for sure. If even after replacing the cable the problem still persists then the user should try another monitor to cross check if the monitor is ok or not.

One reason can be behind this scenario is that the monitor’s cable is broken from the inside, so the user should replace the cable with a new one and try again.

To identify that after switching on the computer the user is instructed to keep pressing the num lock button of the keyboard again and again, if the num lock led is blinking properly it is the signal that the computer has been started properly only the display is not coming, hence the problem is only about the display, everything else is just fine. If the monitor is Powered On and the cable is connected properly then it can be considered as an internal problem rather than external. Many times, it has been seen that because of just a loose cable the display is not coming. The first thing the user should check that the monitor is Powered On and the video cable or display cable (it may be a VGA cable, HDMI cable or DVI cable) is connected properly. Diagnostic #1- (Checking the external Cable) Now to understand the problem we are going to put the computer into test step by step. The monitor may stay black-blank with no display (in this case first check if the power of monitor is on or not), or it may show some message like “ No Signal“ or “Check Video Cable”.

The symptoms are pretty obvious, that in the monitor no display will pop up after the computer ON.

Diagnostic #6- (Checking the Motherboard, CPU, PSU) “My computer turns on but the screen is black”: Steps to solve this Symptoms of computer monitor no signal problem

Monitor turns off but computer still running