Get it fixed by Microsoft if the 360 is less than 3 years old. Check the back of the system for the serial number and manufacturer's date.
Anyway if it is out of warranty either pay to have it fixed at a mod shop or sell it on EBay.
BTW: Do not use the towel trick that temporarily fixes it and does not last very long at all. The towel trick can potentially result in burning down your house if you are not careful.







