Changed power supply on Acer Desktop now montior can't find it

I'm trying to get this desktop (acer) to work, first I replaced the power supply. Now that its fix when I turn it on it boots up but my monitor cannot find it, I went out and bought a new video card yet I'm still having the same problem. Can someone please help me get this computer working?

 

Does it work on a different monitor and does the monitor work on a different system? It could, however unlikely, be the monitor itself or the cable.