sansui 771 no audio out

P

pinman

New Member
I have a model 771 I purchased new in the early 70's that u until recently worked great. now, it powers up, relay kicks, lights, meter all work... but no sound. when I probed the board with my fingers, I heard a loud hum over the speakers, so I have some output. any ideas where to start.

pinman
 
Register to hide this ad
Tape monitor push buttons 1 and 2 in the out position? Audio muting in the off position?
 
Last edited:
i am a novice at electronics troubleshooting Using a handheld tester, I have tested all 4 of the 2sc-1402 transistors in circuit and 2 showed faulty. i removed them and they checked out okay out of the circuit. should i replace and if so, what is the recommended part?

is there a suggested route i should follow?

I did make sure the switches were correct.

thanks.

pinman
 
If the relay is engaging, and all the controls are set properly, you should be getting sound. Even if a couple outputs were bad, you would probably still get distorted sound.

From what you describe, the outputs are most likely OK.

Double check the speaker connections at both ends. Make sure if they are connected to A speakers, you select A, and if B, select B.

What source are you using? FM? Check antenna and FM muting button.

Aux? Make sure if you are in Aux 1, you select Aux 1.

If that doesn't work, it's time to check the input to the amp board to see if the preamp section is outputting audio.

Rob
 
You must log in or register to reply here.
Back
Top Bottom