Transfering to digtal from Mitsubishi VCR?

I bought a Videomate C200 (capture stick) to digitise (to DVD)from VHS pal, using Mitsubishi VCR, model HS-M50V(B).
However, only the sound is present, with no picture on the preview screen.
I have been told that I may need to switch the VCR from RGB to Composite to receive picture, but I do not know if this is correct
or how to do it, or if it is possible with this VCR.
There is no Mitsubishi service in the uk for these VCRs, so have been unable to resolve problem.

Please advise on solution to this problem.

Regards,

M. Marsh