Hello,
I’m new here because my DCC600 has the same problem.
I did the servicemode tests and it passed all hole tests and tray test ok.
At last I found out that there is another sensor in the red1 mechanism that checks if there is a tape inserted. The signal goes from the red1 to the mainboard an from the mb to the front board and it ends at pin 10 of the processor. It should be 0 volt if a tape is inserted but mine is 5 Volt. So the proc. says “no cassette”.
Thought of grounding the signal by hand, but this is a hack I only will do as last option.
First I will remove the mechanism and take it apart to find the broken switch.
Any hints how to take it apart and put it togehter again?
Forgot to say: The service manual has many errors, as wrong numbered pins and connectors and so on. Even the way how to do the service mode tests are wrong. For example: mark erase for key test, but it really is mark write.
Greetings
Ralf