After installing an application I restarted the computer. All of sudden the monitor is blank and no display. The monitor cables are tightly connected. How to set ready it?

It may happen sometimes and follow the below steps and check if the monitor is ok...

1. Check to be sure that the Monitor has power and that the light is on.
2. Disconnect all devices except for the mouse, keyboard and monitor. Reboot your computer to see if the issue is resolved. If it is, then it is one of the devices that you have disconnected that is causing the problem. try connecting them one at a time and rebooting each time until the original problem occurs. Once identified, try reinstalling the device and updating the driver to resolve the issue.
3. Try connecting the monitor to a different PC using the problem monitor's power cable. If it still doesn't work, try the known good monitors power cable.
4. Try unplugging the monitors power cable, then wait about 20 or 30 seconds and plug it back in.
5. If none of the above troubleshooting steps does not solve the issue, then it is likely that the monitor is bad.