I got the red ring a couple months ago but i didnt have to send it in because i was able to fix it. I told my friend to do the same thing and it worked, but it didnt work for my other friend.
So before you send it in try this:
Turn off the xbox.
Unplug the cords.
Take out the hardrive.
Plug in the cords again. (without hardrive in)
Turn on xbox , if it works keep going. if not ur fucked.
If it works, turn it off again.
THen unplug the cords again.
Put the harddrive back in.
Plug in the cords.
Fire it up.
Hope it works. Lemme know