ibm laptop runs in setup only

Hi,
I have an IBM 760l laptop that will only run in IBM setup or IBM utilities. It will run as long as I want to leave it running. This is with the battery in or out. Whenever I try and boot it will start the post and get as far as the W98 flash screen and run for a few seconds and shut down. This also happens with a 98 boot disk, it will boot to the selection screen and shut down. It also dowes this if I get to the start menu and try and choose safe mode it sits for a few seconds and shuts down.Any Thoughts?
Thank You!!