Computer Monitor powers on, but no display?

I'm currently working on a computer. The issue was that the PC would turn on sometimes, and shut on and off by itself, so I changed the power supply. Problem solved. Now, the monitor will power on, but no display and the light near the power on button stays orange. I turn the monitor on and off, no luck.



I had an extra video card in my other computer that works, so I took it out, added it to the computer I'm working on, and it still doesnt work. The monitor works fine on my other computer, as I'm using it right now. Could this be a motherboard issue? How can I test this?Computer Monitor powers on, but no display?
I think it definitely could be motherboard, I am guessing there is no beep codes or anything? It sounds like it isn't even doing POST. I just had a thought though I have had this problem when I changed a power supply in the past. Check the voltage switch on the back of the power supply make sure it is at 120.