TV Crown CTV-5345 bad picture over SCART

[solderboy]

I have a Crown TV set CTV 5345 and if I connect an external composite video source to the SCART connector, the picture quality is very bad. It's blurry and has wrong or missing colors. However, if I connect a RGB source, the picture is fine. There's nothing wrong with the external video sources or with the cable. It's a problem of the TV set. What could be wrong?

By the way, the TV was a gift and I have no user manual. Does anybody know where I can get a user manual and/or a service manual? Crown seems to have no homepage.