If your computer screen is not displaying, there are several potential causes and numerous potential remedies.
First, check the physical connection between the computer monitor and the computer itself to make sure they are securely connected. If a loose connection is the problem, reconnecting the monitor and the computer should fix the issue.
If the physical connection is secure, you may need to restart the computer. This can be done by pressing and holding the power button in order to force a shut down. After a few minutes, turn the computer back on and see if the display appears.
If the display does not appear after restarting the computer, it could be that the monitor is not receiving power. Check to make sure the power cable is secure in both the monitor and the wall outlet. Additionally, try unplugging from the wall outlet for at least 10 seconds and then plugging it back in.
If the computer still does not display, try resetting the monitor itself. This can usually be done by pressing and holding down the power button for at least 10 seconds.
If your monitor has built in speakers, check to see if those are the source of the problem. Unplug the monitor’s speakers and see if the display improves.
If none of these fixes work, it could be that the problem lies within the computer itself. Make sure the computer is receiving power, by checking the power cord is secure in both the computer and the wall outlet. If the problem persists after that, you may need to run a virus scan or other diagnostics to identify the cause of the problem.
Finally, if all else fails, you may need to take the computer to a professional repair shop or contact the manufacturer of your computer and/or the monitor to receive more help.