I have just found this vintage forum. Mod's please feel free to move my threads on my 4600 in 'General Forum'  to here.

So, I have tested the mechanism; FFwd, Rew work perfectly with auto shut off . With no tape, play works, The mechanism will not lock with a tape in. If I partly press play, it will playback I can hear both channels. As soon as it latches, it switches off. I think this is because the take up spindle is running too slow under load at Play speed.  Going through the manual I think it is the clutch that is the problem. I have tried all 3 spring positions, no difference. My question is, can the 'shut off' speed be altered somewhere else?

Problem 2.

All the level LED's are permanently on. I have adjusted the slider and even removed the top transport board with no difference. I have noticed on the Radio board, a wire which seems to be off. looks like it should be grounded somewhere in this area marked Tape. see picture.

Thank you