How can I fix my Recorder sound and picture?

LPVR88 Digital TV Recorder
Picture froze mid playback of recorded programme but sound continued. Tried to replay recorded programme from library. No picture, and sound stopped after about 30 seconds. No picture for any TV channels and any sound stopped after 30 seconds. All menu and text functions working
Checked all leads etc. TV working when not in Scart mode for Recorder.