[genesis]

I continue my monologue 😀
a new CPU is on the way.
In the meantime I checked the PROM of the code and it seems intact.

[genesis]

oups wrong topic.

[genesis]

when TR10 is removed and you are sure to receive stereo signal, what is the B-E voltage?

[genesis]

Ok and 2C56 capacitor was originally a tantalum one?

What was the original TR10 reference?

[genesis]

if you have 0v at the base then the light is not turned on.
have you tried to remove the transistor and measure the base voltage again (to see if the transistor is not base/emitter shorted)
you can even measure 2C56 is this cap is not shorted/or has low impedance compared to the 33K resistor.  Especially since it seems to be tantalum one.

[genesis]

and if you never seen what’s inside a beosound 9000 CPU box, here is the answer 😉
(removing the pins is not easy, the pads are very fragile)
(sorry I can’t remove the second attachement ^ ^)

[genesis]

I was wrong, the 30h I2C call is made by the link processor to the main processor.

after more analysis, it’s the main processor the problem.
the CPU seem to be dead. no memory access (ram/prom etc) only the oscillator is working.  so I need to find a new one to replace it and make further tests.

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