Hey everyone im going to try and buy a Xbox that doesn't work and fix it on ebay Australia they say that it can turn on but has no sound or picture how would i go about fixing this and what would the problem be thanks heaps guys.

You should probably wait until you have the xbox in your possession before you come here and ask for help. Don't ya think?

Nobody likes to play the guessing game.

EDIT: and by the way, your topic title is misleading.

if it turns on just fine without FRAGging thenits most likely the AV cable or the plug for it on the xbox. both can easily be worked around.
good luck.