Does anyone know how to get a Dell LCD working on an old card?

E153FP on a Matrox Millenium II AGP Powerdesk

I use my old 21" monitor with my new 4700 Dell system and it works fine. I wanted to use the 15" LCD on my old computer, just for reference/backup/transfer, etc but the monitor shows yellow on the power button and shows nothing. The monitor does work fine on the new Dell system.