Dell all in one display/sound problems

I have a family friend, who just called me and asked me about their pc, i don't have too much familiarity with all in one pc's. i know they are similar to a laptop in alot of ways. His problem is that his display is showing all green and the audio is glitchy. My initial thoughts are that it could be a ribbon cable for the display, or possibly the graphics card. Let me know what you guys think, preferably someone with experience with aio computers.