Question No signal on secondary monitor ?

[JesseGalang]

I forgot to unplug and turn off my power supply when adding more ram. Now my computer's secondary monitor is not being detected, boot up and main monitor completely fine.

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

Make and model monitors? What connections are being used between computer and monitors: ports, cables?

Was the computer off (versus the PSU switch being off)?

Right click an open area of the desktop. Are you able to access the GPU's Control Panel?

If so, check the configuration settings.

Open Device Manager. Ensure that "Show hidden devices" is checked under the View tab.

Do you see both monitors listed under Display adapters?