whatever you do don't try letting someone fix it. i had this problem. youre going to have to send it in to xbox to fix it as long as you have a warranty on it. it won't function at all huh? but if its been tampered with, which xbox can tell( trust me i know) they will send it back the same way you sent it to them. call there number to get all the steps to send it out free of charge.
This may be caused by some hardware issues. It can also be as a result of unplugged cords which can be caused by unplugged RCA jacks. You can resolve this error by powering the Xbox off unplugging and plugging the cords, then powering it back.