One problem sorted....Sourced a replacement music board...Music and bike noises and voices is now A1. One thing it didn't fix was the background sounds. e.g sounds generated by the play field etc. Changed caps , ram,and opto's around the sound circuitry. Still the same . Any clues.....I am stumped. Maybe they are really annoying and could do with out them ,but I would like to fix it any way..  Cheers