Advice on determining video pinouts

[tobias]

My situation: I'm trying to diagram the pinout of a proprietary 9-pin mini-DIN that I know is a combined video and power cable for a backlit LCD. I suspect that it's not digital video, but I don't know for sure. I don't have whatever it originally plugged in to.

Can you give any advice on how I should go about determining the pinout?

Thanks!