Possible heat damage to my MacBook Pro

Question

Hi,
I''m running into an unusual problem that I suspect is caused by heat damage.
This is a mid-2009 MacBook Pro, 3.06, 8 gigs RAM, 500 gig 7200 RPM hard drive.
The Mac has been trouble free for a couple of years, but in the last 4-5 months has been giving me problems. I'll touch it in the morning to wake it up and the white sleep light will go from pulsating to off completely, and I can hear a low whirl come from the computer, as though it were working properly. Despite that it won't start up, and I have to hold down the power key to force a shutdown. When I reboot it the computer is often unresponsive and slow, and I have to restart. Eventually it gets back up to speed.
Yesterday I noticed my cat sitting on the keyboard. I've noticed her do this a lot, because of the heat. I've never thought much about it until yesterday, when the computer apparently froze at 3:26 AM (unlike other overnight freezes this one froze the Finder on the screen.) When I attempted to restart, both my OS X and Boot Camp partitions were non-bootable (or even even visible in Disk Utility) and I had to restore from Time Machine.
I'm now beginning to realize that my cat probably sleeps on my computer every night, and is overheating it by blocking the airflow vents. I have walked into the room and shes been sitting on it with the fans whirring, but I just didnt put two and two together, My basic assumption is that the cat sits on it, overheats it, and then pushes it a bit warmer due to the fact that she's insulating it. (it doesn't help that she's a Russian Blue and her fur is very, very insulating.)  I'm concerned that this latest, worse incident means that some permanent damage has occurred.
So...does this sound like heat damage to hardware? If its the hard drive I'm sure I can just replace it. If its processor-related, well, ugh.
Thanks in advance!

Answer 1

While a cat sleeping on the machine can't do the machine any good, I don't see anything in what you describe that would tell me "heat damage". Note that overheating doesn't necessarily have any specific symptoms—for instace, it may cause some electronic component to fail much sooner than expected (all components fail sooner or later).
If the machine wasn't doing anything particularly strenuous at the time (eg, video rendering), then the heat would be less of an issue.
So far, it's not clear at all to me what the problem is. I'd go through the normal troubleshooting routine—verify disk, check for problematic 3rd party software, etc, including running the AHT, as OGELTHORPE suggested. I'd also take steps to prevent furry creatures from nesting on the MBP. (If you succeed, I'd be much obliged if you shared the secret.)