My Xbox 360 locks up no matter what I do. I can be sitting idly on the dashboard and then all of a sudden the video will freeze and audio will stop. I've tried clearing the cache. I just revived this thing from the RROD with a reflow, and it did it before the RROD too. It freezes within 5 minutes of gaming and 15 minutes of being on the dashboard. The fans never run any faster to indicate an overheat, but still it does this. I've applied thermal paste CORRECTLY. It runs very cool. I just don't know why it freezes..where do I look?