using scart it was perfect, which ruled out hard drive problem but when i went back to hdmi cable it was the same old story, glitching and no sound, I happened to have a spare hdmi cable lying around so I swapped it with existing one in box and hey presto everything played as it should, no glitching etc, so moral of story is don’t buy hdmi cables from 2 euro shop. Many thanks to Graham for prompt reply and troubleshooting tips.
Regards