Onkyo A10 - Power OK, relay click OK, no sound

bit of a job but have managed to swap internals before . have even got in touch with the maker and got new parts to rebuild . cant see that happening here though .
 
I would know even know to do that, cut and weld is all I can think of, neither of which I have access to. if I could get a double ganged 250k with centre detent, I could put it in updside down and run jumpers to the boards. It is the knurled 30mm long shaft the poses the issue, there are decent quality guitar balance pots that might work, but they all have short shafts. I might start pulling onkyo schematics from that era, to allow widening of search for shared balance pots of same value. Thinking out loud here just
 
I'm actually having a hard time understanding why it needs such a long shaft. It's on a board next to a push button switch that ostensibly gets screwed to the chassis frame. And it has a threaded shaft which uses a nut to fix the pot also to the chassis frame. Just how far does the faceplate stick off the front of the chassis frame to require that long of a shaft? The sub question being, other modern pots also have the threaded shaft for the retaining nut. So, even if the pot is fixed to the frame and jumper wires sent to the board, the shaft would be too short? :dunno:
 

In the picture the balance pot is mounted.
So the shaft length makes it perfect fit for the balance knob to be fitted while pot is soldered to board.
If I can get a suitable replacement I can just jumper it as you have said and shaft length becomes less of an issue. Problem I have is knowing whether I need a dual ganged 250k pot, each gang 250k, or is each gang half that, 125k per gang.
Also picking a quality replacement is hard as I am pretty green still. The internet abounds with 250k pots, I cannot tell if they are quality or some poorly made Chinese junk.
 
Thanks Pete, your input is invaluable as always, thanks.

So i will definitely need a dual gang pot then no?
OR (maybe stupid question here) are they wired together and a single shaft controls the balance?
 
I think you bought the amp from me so following with interest.

It was taken in part ex for a repair I did for a polish gentleman, it had been stuck in a corner for 5 years.

I did price up for a recap hence those sharpie marks on the caps but I decided that the price it just to sell didn't work out, don't know what could have happened with the pot maybe Jarred in postage or broken when taken apart at some point, and yes it was very dirty inside.
 
Mate; I know you'd like to get it working balance wise. If not interested in selling and repair later you could just reintall the old non working pot for looks inverted and put a balance pot in the rear wired in. how often do you adjust balance? I rarely do... just to see if the pots working I guess.
 
I'll do that for the big filters but only after everything is up and running.
The sx525 seems to have the same 250k dual balance pot, quick check on eBay shows
 
UPDATE:

Probably against the advice of AK, please do not shoot me :crazy:, i have gone ahead and recapped just the equaliser, preamp and protect board. Had the parts, unit sitting there so i said why not.
100% sure each cap is done perfect orientation wise and a lovely touch by onkyo is that, on the boards is that the minus and neg are marked on the solder side of the board, found no inaccuracies either. One cap at a time is how i did it.

I did not touch any of the transistors, slowly learning a lesson on this!!!!!

The i took another mad step and cleaned the preamp, equaliser, power and protect board with window cleaner (ammonia free) a super soft brush and rinsed in filtered water, followed by rinse in alcohol.
Far from perfectly clean but a hell of a lot better - unit is now sitting beside a good dehumdifier
It will sit there for a week or two anyway until i am sure everything is dry.

I have a bunch of resoldering to do, lots of ifffy looking solder joints all over the boards.
Question - Do you generally add a little bit of solder just to reflow, or soldapult and then redo the whole thing?




Once all this dries out, i am going to disassemble the rear of the unit and tackle the chassis.
Serious cleaning required. I just do not understand how it got so dirty - someone was using it as a plate for greasy fry ups, and or an ashtray for the old moroccan woodbines.

Meanwhile i am still on the search for the 250k linear dual gang balance pot.
 
You could always put it in a low oven to dry out. As long as you keep it below 85C you’re good. Make sure the cord or any other part comes into contact with the heating element.

R.e. The pot... have you checked Maplin Electronics? I found one there for a Yamaha variable loudness. It had a plastic shat which I had to cut down to length and the make scores in for the knob to fit it, but function is what I was going for.
 
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