[QuadList] ot Help with a Betamax Circuit Diagram

[Dale Lamm]

Sorry, never worked on a 420. Other helical tape cassette machines I did 
work on had photoelectric sensors to detect things like "broken tape". When 
you had a chassis on the bench under strong light, you needed to mask off 
these detectors.

Also, sometimes the threading ring just gets gunked up and needs a good 
cleaning and re-lube. You did say you could wind the cassette, I assume you 
mean to thread the tape over the complete path.

GL with the 420.

[snip]

Whilst everybody is talking about Circuit diagrams I would be grateful for
any help with a Sony Betamax SLO 420, The machine will not load a cssette,
if you wind the cassette compartment by hand it will then load and play. I
have checked the compartment  and that is seeing the cassette but it is not
loading it. The fault appears to be on the SS10 board, but all I can see it
do is go into a big square chip and a little sub board !

Funilly enough it will eject the tape !

[end]