The monitor
If you can troubleshoot the problem without opening your computer, that is best. So, connect a known working monitor to see if it works. If not, I guess you have to suspect the video card. :)
The Video Card
A monitor is an output device. A touchscreen monitor is different. The touch panel, which is installed over the monitor is an input device, but the monitor itself is strictly an output device.
Put a known good device in that port...process of elimination!
Normally it is an output device. However a touchscreen monitor is both an input and output device.
monitor is an output (display) device
A Monitor is an output device, but a CPU is not
A monitor is an input device only if it is a touchscreen.
out put device
monitor
A normal computer monitor is simply an output device; it takes no input from the user. A touchscreen monitor, on the other hand, is both an input and an output device.
computer