My console started freezing and getting corrupt graphics then a few days later I started getting the 3 red lights of death.
Microsoft gave me an address to send the console to and a service number. I was a bit worried about sending it in with a broken warranty seal.
I didn't want to try the heat gun method so I decided to send it to them. The address Microsoft gave me was some electronics company, I figured they would be under contract from Microsoft to do the repairs and would get paid on a job basis so probably wouldn't give a shit about a broken warranty seal.
I opened up my Xbox reflashed the firmware to standard and polished off the warranty sticker all together. I was going to claim ignorance if queried about it.
I sent it in and about a week later got a brand new Xbox 360 in the mail. Nobody every queried me about the warranty sticker.
It has a Hitachi drive in it, I haven't opened it up yet to see what firmware it has but I am pretty sure that it will have a 78 unflashable one in it.
I don't think I will even bother to open this one up unless a homebrew hack comes out.
P.S. I am a regular poster but used a temp account as my forum name and Xbox Live name are the same. Just in case someone from Microsoft reads this.