This may help or not, but some laptops have a problem with the fans... My Dad had a Sony Via and that fan stopped turning... caused the thing to shutdown after an hour or so and wouldn't restart until an hour or two. If you have waited over two hours and it still won't work, then either that isn't the problem, or the thermal sensor was malfunctioning or set to turn off too late....may have burned up something. Just a guess but I thought I would put my two ¢ in. The power supply may have fried too. It does sound like a hardware issue and unrelated to the OS or software. If its still in warrantee, you should get it replaced. If it is older, the company may still fix it for a small fee.
Most likely the processor or power supply if it won't start up after plenty of time to allow for cool down.
