sony betamax c9 audio trouble
 

picked this up cheaply second hand recently, after cleaning tape path
i have good picture on playback but muffled audio. Alignment is Ok.
When recording, i get no audio on either left or right channels, and
the pic has flashing colour.

Not being particularly familiar with Beta , is this likely to be the
a/c head which needs replacing? anybody have a schematic? I would
really like to save this classic old machine if feasible.
thanks for any suggestions
regards
B.