Hello guys
Because the unit is old (but only occasionally used) the loudness button causes some noise due to bad contact
sprays did not work, so i decided to jumper the pins that it connects on the pcb at the on (loudness on) position
i did that and it worked fine, i know from the bottom of my heart that the switch connects 2 pins and also d/c other 2 pins
on every position it have (6 pin switch), so i was curious what would happen if i clicked the switch off while the jumpers are on, when i did so the sound is gone, nothing blew
all lights are on normally, except that the unit does not click its relay anymore and ofcourse no sound
where the problem could be?
hope to find help here
thanks in advance

 

Post deleted.

 

Pioneer amplifier A-205
it is written in the title

 

That's why I deleted the post. My bad.

Messy schematic, low quality photocopy, hard to read. Still searching for the loudness switch.

ak

 

No problem my friend
I have also found that scanned pdf
not so helpful, would it help if i photographed the pcb for you at the loudness switch area?
I really did not imagine that such a switch when turned off and on at the same time would cause such a prob, i wish i never did that, the unit is so dear to me

 

Without the circuit it will be a challenge to see what would be damaged

 

Without the circuit it will be a challenge to see what would be damaged

ok i did found a much better version for the service manual
https://www.audioservicemanuals.com...er-a-103/2455971-pioneer-a-103-service-manual
these versions are so close to each each inside out, plz check it and let me know
thank you

 

thats a capture from the pdf link i just shared

 

thats a capture from the pdf link i just shared

The small portion shows the switch, I guess, but not the relay or connections..So not muc evaluation is possible, although it may be that s fuse has been failed someplace.

 

The small portion shows the switch, I guess, but not the relay or connections..So not muc evaluation is possible, although it may be that s fuse has been failed someplace.

how about that detailed pic for the other pcb
btw there is-15v but no+15v

Q321 is ok (tested out also), i also checked many fusable resistors and found none that is blown

 

The link to the manual takes me as far as page 2, while the schematic circuit is claimed to be on page 6, which does not seem to be available to me. And the image of the PCB is no help to me in following the circuit due to my lack of X-Ray vision. I am NOT Superman, the one with X-ray vision.