i don't think they can tell, ive done it and sent my 360 back, cuz you have to wait for them to send you a return box for the 360, so in that time, and that was about 3 weeks, i was using the towel technique, all it does is heat up the circuit board the the components connect again, cuz the red rings come when some of the motherboard components stray away from each other in so many words, and that ofc courses hardware problems.