I had my 360 die on me today; 3 red rings and all. The best I was getting was a logo followed by a freeze up at the dashboard. Forget about playing games or video. The secondary error codes were showing 0102 and I wasn't crazy about putting a heat gun to my $400 console.
A number of months out of warranty and with nothing to lose, I opened up my console to see if anything was obviously loose or out of place (and to provide the best airflow I could get). I spent a good portion of the day searching forums and trying everything I could think of to get the console working short of mods or resorting to a heat gun, but I was having no luck. I was prepared to buy a heat gun and see if I had any luck, when I ran into a post talking about using artic silver on the heatsinks, and especially to make sure the heatsink screws were tightened securely.
I figured what the hey, and I tightened the 8 screws on the heatsinks roughly 3/4 turn until they seemed secure. Amazingly, the console booted, went to the dashboard and successfully launched a game (first time all day). Even better, it didn't freeze when I was playing. I shut the console down, and turned it back on to see if I was just lucky the first time. It booted again (another record for the day). I played another game, and again no freezing or errors. I put the case back on, turned it on, and again everything worked fine. I've successfully booted and played games 5 times in a row today with no problems, when I haven't been able to even boot twice in a row all day.
My theory is that the screws on the heatsinks are apt to slowly loosen as the temperature in the case changes. Eventually they become loose enough that it causes errors. I'll further speculate that some of the success of both the heat gun and artic silver fixes might simply be that in the process of removing and reattaching the heatsinks, they become properly tightened again.
In short, before you try anything drastic, you might want to check and make sure the heatsink screws are secure. Hope this helps someone.