@iandaemon I was transferring files via ftp on ssh (laptop on wifi, pi on ethernet). I’ve tried a different sd card and still the same so have ordered a new hdmi cable coming today to try that. If not I guess it’s the Pi itself. If I change themes I also lose the sound as well. I do now believe it’s hardware issue, still driving me mad! Thanks again for replying.
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first