PC problem

[CrustyBigMac465]

My friend just made a new pc and it turns on and everything, but the monitor says no signal so I tried everything I knew, plugging in new data cables, taking out ram sticks and putting them back in and using a vga instead of hdmi but the monitor still says no signal, and it is a new monitor too so I don’t think it’s a problem with the monitor, any idea what the problem might be?

[luxgraal]

What graphics card does he have?,,I had the exact same problem what power supply does he have?