Ultra fast Overheating with no aparent reason
Hello guys. I have a xBox 360 Slim (model 1439), bought it 4 years ago aprox. Last 3 years it was in storage (clean and dry) and arround a month ago I unpacked it again. I have been using it since then everyday, and everything worked the way it should.
Yesterday I turned on the xBox, and after a couple of second the fans started to make a very strong noise, and in less than a minute the green power dot light became red and started flashing, no other light, and a message saying that the xBox was shutting down to prevent damage by heating appeared. Here I leave a link to the official xBox article regarding that problem:
After that, the xBox shutted down partialy, becouse it kept cooling the console. After half a minute aprox the console finally shutdown. When I did restart, the message regarding cooling down (in the above article) appeared on screen, but it didn't gave me enough time to read it becouse again the Power down because overheating message apeared.
Since that moment, everytime I turn on the xBox, after no more than a minute, it shutdown for overheating. This is what I've done to try and fix it:
1) Try another Power Supply that is working on another xBox, same thing happened.
2) I fully disassemble the xBox, except the T8 screws, so I didn't remove the heat sink. It was almost shiny, no dirt at all.
3) I unplugged everything from the xBox, A/V output, Kinect, Net Card, CD/DVD Reader, SATA Disk, leaving only the fan and the motherboard (and the other board wich has the lights and power control, I assume). Same thing happened, progressive fan speeding, after a while red flashing light, overheat.
NOTE: I managed to realize that if I plug the RCA Output and give signal to a TV, the heat is much faster.
The curious part is that this massive heating event wasn't progressive, meaning, untill yesterday, fans worked very very quietly, and my xBox never had a problem before, not even a single one.
So, what do you think, what can be the cause, and what can I do to fix it?