My Zenith ZDS-625nlc 386sx video card seems broken.

The LCD monitor stopped working months ago, but I could still link the laptop to an external monitor or a TV with a VGA connector. Now it looks like I can't see anything on an external monitor anymore. I have tried to launch Doom "blindly", and during the demo loop I saw the external monitor flashes yellow when the marine picks up the items and red when he gets hit. But that's all I can see.

It's not a matter of cable or monitor, since I have tried to switch them around and they work 100% fine with other computers as well.

Does anybody know if there's a chance to fix this? Thanks in advance if you do! I will try to post some pictures later on!