Some of the posts take a LONG time to refresh here.... like 6 min !
2511 Protect board:
Protect relay
Yellow ( out of the BRICK ) is left ( 2509 is the part # OF the bricks PCB) PIN N goes ( on a large Yellow wire with a female spade lug ) to protect board relay IN pin 19 Pin 20 is the OUT to speaker switch
Red is right 2509 O goes to protect relay IN pin 18 pin 21 is the OUT to speaker switch
1) Check the red wires going in & out of the protect board
2) Hook the speaker up to the right channel
3) turn the right volume down 1/2 way
4) turn amp on ( hold ears )
5) IF NO AUDIO on speaker back probe pin 18 on protect board
IF audio is there
6)Back probe pin 21 on protect board.. IF YES clip lead speaker to 21 and chassis GROUND and see if you have audio
When you have a connector in place , in this case a male on the PCB and a female connectiing to it.. there is a shell on the female connector to prevent from shorting.
Using a paperclip ( or similar ) with a cut tip ( at a 45 deg ) you slide the paperclip in the backside of the connector so you can make contact with the actual metal bit of the connector
#1 NEVER ADJUST BIAS WITH PROGRAM
#2 The amp is shutting down due to lack of stable voltage, we need to go up to 75 watt DBT or 100...
The amp needs MORE power, because you are putting a load on it
So Audio in UNDER 35 !
Extra wires & De molexing.... these are all stop gap repairs typically for worn or broken connectors.
OR to get around this....
The black or green death
Sansui made a BIG DEAL of GOLD PLATED connectors BUT they cheaped out.
The Gold was usually only on 1 of the 2 connection points and it was plate on tin.
So when you have dissimilar metals, over time these corrode.
You develop many heat cycles, and connections get funky, resistance builds up and POOF.
So it became practice to neuter all the connections for a more POSITIVE contact,
This point can be argued till the cows come home, but cleaning on initial rebuild or replacement
will let these units live on for another LONG period of time, unless you live near the ocean or other body of water..
Then all bets are off unless you used Dielectric grease