I found this thread, I know it's 3 months old, but it was still good to read so I'll go ahead and respond.
I spent alot of time trying to diagnose a fan problem on a Dell Inspiron 8100. laptops make their fans turn on and off all the time, which is kind of stupid, because the silly fan circuit will wear out before the rest of the computer does, the little transistor starts shorting out and screwing up everything, screwing up your bios.
the problems you are having where it won't boot sound like a messed up bios.
Anyways, I wish I knew why they don't just do like they do on desktops and just turn the fan on and leave it on, then it will never ruin the computer, since there's no transistor in the fan circuit, much simpler, who wouldn't rather put up with the little laptop fan noise than have to get a new motherboard or throw their laptop away because the fan circuit is ruined? the laptop fan goes on and off constantly anyways. so dumb.