as everyone nos that xbox360 is wick of heatsink,with many hours working,the high temperature will destroy GPU,than dots black,oxidation,unsolder...RROD.
what i do is:

dots black pads without or bad contact reballing with new solder balls
but u also need to take care it very well...... don't keep it working more than 4 hours one time. "after quiting a game to leave my Xbox ON, on the dashboard for about 15-20 minutes, so the temperature could lower a bit, and afterwards shut down the machine" (posted by Serhan)


when u c the temperature indicator shows ur a big number,pls leave it alone for a while,have a rest,give a call 2 ur girl friend...whatever,just a break.
sth else? yes....if u have any quetions about ur consoles,xbox360,ps3,psp,wii....feel free 2 ask me,write here,email me,or come 2 me.am here always.