First go round the back of the DVD and make sure all the leads are plugged in properly. Could be a loose scart lead. Make sure both ends are in nice and tight (both the dvd end, and the other end in your tv or video)
If that does not help, it could be either a faulty lead, or your friend may have played around in the setup menu,
Look for a menu (or similar) button on the remote, find the setup section, and look for output type, or similar, you usually have a few choices, RGB, YUV etc, try each one in turn to see if it helps.
http://www.lasermemory.com
lasermemory, August 2004