HP900 Laptop overheating and admin/bios password

I have an older HP900 laptop which is a nice size to take in our motor home. However, it overheats after running for about 15 minutes. I understand there is a bios update that turns the cooling fan on sooner but I can't get into the bios because of password protection. Any ideas on how to crack the password or any pins to short to reset it?

The laptop will run fine if I rais it off the table and have a fan blowing on it from behind. Cooling fan in laptop runs, but it only comes on shortly before a shutdown if I am not running an additional fan blowing under it.

thanks for any ideas or help

Woodie