I came home yesterday to a frozen MacBook Pro with a crackling sound coming from the upper right hand corner. I shut it down, but haven't been able to boot up since. I either get the plain gray screen or the Apple logo/thinking gray screen. I reset the SMC, but when I try to reset the PRAM or boot into safe mode, it immediately powers off. Same thing with trying to boot from the Install Disc. I ran the quick hardware test, which returned error code 4sns/1/40000000: TCOD 107.375. Googling tells me this is fan/temperature/possibly logic board (!) related. So my question is: should I try to boot from a backup, should I remove the third-party RAM, should I take it to an Apple store, or am I just hosed?