So i picked up an xbox the other day that was working and decided to clean it up because it looked like someone had spilt something inside (rusty metal cage). while i was there i thought id change the thermal paste, just to prolong the life out of it really. I got it all back together and now when I power it up, sometimes it will flash red/green and sometimes it will start for about 10-40 seconds and then switch off. I personally think I may have gotten some of the solvent under the gpu as well. so I am thinking the first thing ill try is drying it out with some 99% isopropyl. fingers crossed!