my xbox used to belong to my friend until it got the red ring of death. he left it in my possession and i fixed it. (i opened it up and replaced the x-clamps). it was working for about 2 weeks when all of a sudden it started overheating. i opened it up again and replaced the thermal paste and adjusted the screws but it only works for upwards of 5 min. i even left the console open with a big fan blowing into the heat sinks and then it lasted for maybe 20 min. is it fixable?