Just installed a new cpu fan and have put the system back together but now the monitor is acting like it is not connected. Graphics card is powered with the fan spinning so it is getting power but it somehow is not picking it up.
Also tried an hdmi cable to connect to a television and did not pick it up the signal so I believe the cord is working.
More aboutmonitor recognized connected
I know this may sound redundant but check that everything is plugged in. In a simple take apart and rebuild this is one of the most common problems.
Does the system beep when you first turn it on (during POST)? (Note: this only matters if it used to do this).