Ive got allmost the exact same thing on my box, difference is that it boots up fine, but when I try and play Halo2, it will stutter, graphic glitch, the halo logo takes a couple of minutes to load and then finally, when at the log in screen for multiplayer, I have 2/3 of my screen covered in graphic artifacts, cant join a XBL session or even play single player campaign.
I have 3 copies of Halo2, all PERFECT condition, same results, I get some graphic glitches in other games, but they seem to be 90% playable.
About 3 weeks ago, I got the 3 red rings of death, noticed my system was VERY hot, shut down the system, turned it back on and it has been fine up untill last night.
Luckily, I bought mine at launch at Samsclub, they kept my receipt in thier computer system and will exchange it for a new system.
Bottomline, dont let your 360 overheat. bad things happen.
Good luck to you.