Free laptop keyboard not working

Hi all,

I recently received a free laptop from a guy at work that he said his wife and daughter had become tired of messing with.
He thought I would like to gut it and see how things were laid out (I have built numerous desktops for folks at work)
The complaint on the laptop was the battery (replaced with a new one) would not keep a charge nor read as charging.
The laptop usually would not stay on more than 10-15 minutes while hooked up to wall outlet and the fans ran non-stop(new power supply and cord)
I imediately thought overheating due to dust, the guy told me "hey if it works great if not have fun"
After several tries to work around the shutting down (keyboard was not working then) I decided to pull it apart, cleaned thoroughly, reinstalled everything (new thermal paste on the cpu heatsink) and it has run 8 hours almost silently.

I can use it with external keyboard and the device manager shows only 101-102 ps2 keyboard nothing else ghosted to switch back to onboard keyboard. am I missing something obvious or is this the end of this keyboard.

thanks fo any input

Scott

HP ze5477 wm
windows XP home