I recently won a 360 off eBay for cheap, advertised with the 3-ring red lights problem, flashing as always and displaying nothing at all on the TV. So I left it on for about 4 hours and just switched it off, then switched it back on again...and now it's working!
WTF? So why did that happen? So far it's working fine with games and everything, but...why would leaving the console on for a few hours suddenly bring the console back to life?