Ok, so I downloaded service manual and find a mute mechanism. I was thinking one of transistor (TR102 or TR103) is broken. But the mute mechanism works fine. Then I was following signal from cinch to the IC11 (Operational amplifier LM833n). I do not have oscilloscope so I was able to measure DC voltage only. I was comparing output of the IC11 to IC12 (the same IC but for left channel which is working). I found the voltage on pin 7 of IC11 is 11.23V, on the same pin of IC12 it is 2.69V. The IC is amplifies signal from TDA 1541. Right channel is pin 6. I was again comparing output of pin 6 to pin 25 (output for left channel). Difference id here too. Pin 6 of TDA is 2.84V, pin 25 is 0V (or very low under 20mV).
Can we say the TDA 1541 is wrong and must be replaced or there can be an issue in the digital part? Or the value I found are normal (I tried to find some info in data sheets but I am not skilled enough to understand it well)?
Login to view image