Pioneer amplifier A-205 Relay not clicking after a mistake i made

[GraphicMan]

I doubt there is a DC problem with the amp section, if there was the protection circuit would engage and you would not have any output. it is likely something in the signal path that is at fault. If you can access the plug AKP1044, use a metal pin held by your fingers to inject signal (hum) at pins 1 (right channel) and 3 (left channel)

dont know if that is a good or a bad news, i did not find the converter so i used these 3 pins as mentioned in the pic and there is clear sound coming to the head phones from both left and right pins
plz confirm that my assumption is correct on these pins

this means there is no issue in the path of the input signal?
if so, where is the problem then?!

can you please guide me where is that AKP1044 connector on the actual pcb?
attached is the pcb after cleaning and re flowing some joints (already tested and worked at that stage before the assembly)
if the connector is not on that pcb where is it?
thank you

[R_J]

I doubt there is a DC problem with the amp section, if there was the protection circuit would engage and you would not have any output. it is likely something in the signal path that is at fault. If you can access the plug AKP1044, use a metal pin held by your fingers to inject signal (hum) at pins 1 (right channel) and 3 (left channel)

[GraphicMan]

Does the speaker switch have any effect? also do you have any headphones to try? The amp output runs through the headhphne ass'y board before it goes to the speakers.

the speaker switches has no effect also , on top of that i never had any scratchy noises from the speaker switches also
they are just A and B, i am always using the B, and it works but on right channel only

i have an earphone but with the small jack, i think i have a converter, will try and let u know
thanks

[R_J]

Does the speaker switch have any effect? also do you have any headphones to try? The amp output runs through the headhphne ass'y board before it goes to the speakers.

[GraphicMan]

btw there is actually a much cleaner version of the schismatics R_J shared it
https://elektrotanya.com/pioneer_a-1.../download.html
in case it helps

[GraphicMan]

hope this helps

yup i actually found it before i read ur post, however i wanted to make sure where it is on the board
attached a screen from the board, where should i short with my wet finger tip?
thanks a lot

[petehall347]

i would like to do so but can u plz tell me where is that capture, perhaps the page number or a wider capture, i cant figure out where is that section
thanks

hope this helps

[GraphicMan]

right down dirty testing . lick your finger tip and touch where the arrow is pointing . expect a loud hum from test speaker .

i would like to do so but can u plz tell me where is that capture, perhaps the page number or a wider capture, i cant figure out where is that section
thanks

[GraphicMan]

Start by checking everything you took apart, maybe you damaged a plug or cable during re-assembly

i have also done that, there was indeed a cable with a single pin not very tight, but it turned out it is not the issue
i am sure the unit was great right before the assembly and i am usually very careful during it, really strange
how about you guide me with tracing to narrow it a little?
thanks

[petehall347]

right down dirty testing . lick your finger tip and touch where the arrow is pointing . expect a loud hum from test speaker .

[R_J]

Start by checking everything you took apart, maybe you damaged a plug or cable during re-assembly

[GraphicMan]

guys i am stuck
is there anyway to narrow where is the issue?
can somebody give me some steps to start with? at least to make sure that no rare/expensive parts are the issue
waiting

[GraphicMan]

I also tried to use other inputs, CD instead of line in, same issue

[GraphicMan]

i found very good continuity from these points to its related speaker out screw sockets from the back
hope this narrow things a bit

[GraphicMan]

I have a little another issue now
for some unknown reason after the assembly i cant get any sound from the left output, i tried everything, swapped the input jacks, swapped the output speakers, but nothing comes from the left side
where can i start diagnoses for this? i just want to make sure it is not a serious problem, it also does not seem to be a scratchy knob or a bad switch because nothing at all comes from the left output
thanks

[GraphicMan]

It’s a Class AB. No way that thing is Class A.

i think u r right, but how did u know?
however i did notice that its wattage is not really affected by the signal nor the volume control, it is connected to a power meter, so i can see precisly how much it is drawing
i heard the class A is the best in quality but least in energy efficiency, are class A more expensive also?

[CapLeaker]

It’s a Class AB. No way that thing is Class A.

[GraphicMan]

btw i am curious to know what class is that model? A or AB or something else?

[GraphicMan]

again my bad, i was not connecting the prob properly, too afraid to short next to the gnd pin
the +15 is there very exact
thank you again for the much better pdf, that helps a lot (assuming it is the same schematics)
i really did notice way deeper BASS! after that repair, coz i also did disassemble the pot , it was so scratchy , i even needed to mill a small copper ring with a stick (0.1mm thick) and placed it on the inner carbon resistant ring, the outer was not worn out, so the inner of the left channel was causing the issues, no the loudness switch is much better, the direct which is so big switch is very scratchy , i need to disassemble and clean it, but these switches are really hard to assemble , it is very very complex and delicate, if it gone perhaps the whole amp wont work again, and wont even know what it does to try to replace it
you guys are really good at what u do, thank you very much for your patience and help, u r a life saver

[R_J]

If the amp is working the voltage is likely ok, which is "the" connector, or you are checking the wrong pin on "the" connector
Check connector AKM1037 on Power amp board or (AKP1044 on control ass'y) pin 7 =+15 pin 5 = -15
The service manual from the Pioneer A-103 is very similar and a bit better quality and easier to follow (but too large to upload here)
https://elektrotanya.com/pioneer_a-1.../download.html