Xbox 360 freeze, no image, no connect?

[Master Ted]

Man that happened to my friends Xbox 360. He turns it and nothing works, just the light, its basically just a big metal box that you can use for a night light. Me and my agreed that it was he graphic chip going bad. So I took the 360 apart and dispatch the box shape heat sink and tried to put new Artic Silver, but all I got is a 3 ring. But after I done it another time, it started to work , but yet it didn't do anything.

 

[Ben]

My little brother was playing the 360 this morning and it suddenly froze and shut off. When he turned it back on, it powered up but no image came onto the screen. Also the 360 wireless controllers won't connect, even if i plug it in with the charger. My warranty is expired and i don't really want to send it in if i don't have to. What could be the issue? Do i need to send it in or can i take it apart and fix it myself?