I attached an additional monitor to my IBM ThinkPad g40 laptop using the external monitor port. The first time it worked fine. After disconnecting the additional monitor, subsequent attempts to connect resulted in the monitor "shorting out." If I forcefully push the cable connector into the port, it works, but if I release the "extreme" pressure, the monitor goes blank, or the screen has a yellow or green "film" over it. The monitor works on my desktop computer with no problem. The pins in the cable are not bent. Could the external monitor port be faulty? Can it be replaced? Thanks for any help.