Sansui G-9000 in protection dc offset

[G-901]

The receiver is in protection, speaker relays do not click on. Was testing DC offset at terminal 27 and 28 and am getting -2.5vdc tried to adjust it on driver boards but would only get down to -2.2 Vdc I’m at a loss as to what it could be.

Any help would be much appreciated

 

[G-901]

Was able to get the offset to 2-4 MV DC after I found R21 to be hi Rez. But the receiver is still not activating the speaker relays and is still in protection mode.

 

[LBPete]

When it is in protection, the protection relay disconnects the speaker terminals from the amp. If it's in protection and you are trying to measure DC offset at the speaker terminals you are wasting your time. You need to check it at a point prior to the protection relay. Measure it at R61/R62 on the power/protection board. These resistors are in parallel with copper coils in the output circuit. Measure between each of these resistors and chassis ground.

- Pete

 

[G-901]

Thanks Pete! I will take a look at that and let you know what I find.

 

[G-901]

I adjusted r61 to 1mv and r62 to 0.6mv but it still stays in protection

 

[avionic]

Trouble shoot the power supply / protect circuitry.

 

[G-901]

On the power supply board
Pin 3 is -0.266 vdc
Pin 2 is -0.254 vdc
Pin 5 is 0 vdc
Pin 6 is 72.6
Pin 7 is 73.6
Pin 1 is 43.2 vdc
Pin 39 is 43.2 vdc
Pin 37 is - 43.2 vdc
Pin 18 is -43.6 vdc
Pin 12 is 71 vdc
Pin10 is -71 vdc
Pin 16 is -43 vdc
Pin C is 2 mV
Pin D is 2 mV
And pins 29-31 are at 0

You can see that pin 37 and 39 are at 43 Volts instead of 33.

I will continue going over the board. Thanks for your help