Ibm laptop T40 Video freezes

I have an IBM T40 laptop. After about 5 minutes (time is random) I loose my video. When I have it in the docking station and a "big" monitor is plugged in the same thing. the video goes blank but the lap top is still on.
I have already tried the screen saver properties when the hybernate shuts doen video. I now have that it never goes into hybernate.
Does ANYONE>>>>>>>>>>>>>>> have an idea on what to do. I am about to open the keyboard to check the data cable to system board. Thanks for your time it you know an answer.

IT_Eagle
Big boston college football fan and we have a big game against Fla St Saturday.