Bass constant sounding

[nagant27]

So I have an accordion with a bass note that constantly plays on the push and pull of bellows. It’s G.
I’ve removed the reed blocks snd the pallet looks closed, and springs down like it’s supposed to. The bass buttons all seen ok too.
Is my next move to disassemble the bass machine? I know how to do this snd have done it, but I just want to make sure that’s what I should do next. Any suggestions?

 

[Gonk]

I'd use a light test. With the reedblocks off, go to a dark place and shine a bright light through the bass mechanism. You'll see where the faulty pallet is.

 

[JIM D.]

Observe the G piston -- it might have jumped a pin.

 

[nagant27]

Thank you both. I ended up taking apart the first 2 rows of bass buttons, 7th and dim. Here I could see where the piston with a pin that was on the wrong side. It was a jumped pin. Easy enough.

 

[Dingo40]

So Jim nailed it!

 

[JerryPH]

Jim rarely misses!

 

[nagant27]

So I was thinking about the problem I had snd was wondering what if the sounding bass was only on the push or only on the pull of the bellows? Would this indicate the reed itself a problem? What other causes would do it? Just for future trouble shooting issues.
thanks as always.

 

[debra]

So I was thinking about the problem I had snd was wondering what if the sounding bass was only on the push or only on the pull of the bellows? Would this indicate the reed itself a problem? What other causes would do it? Just for future trouble shooting issues.
thanks as always.

There are different possibilities in such a case: it could still be a jumped pin but combined with one reed being blocked as well (by some debris, or a reed not straight above the hole it's supposed to go through, or a leather that doesn't open). It can also be a weak or broken spring causing the pallet to be blown open (on push) and sucked closed (on pull)...

 

[JIM D.]

If the bass note constantly plays with the bellows in any direction, the first culprit to check is always to look for a jumped pin !!!
It's the problem 95% of the time. Also in most cases this is caused by a bent bass button & piston.

 

[nagant27]

Ok, that makes trouble shooting much quicker. So that’s really the “go to” fix in most all situations. That’s good to know for the future. I’m sure I’ll run across it again, and now know what to look at right away.

 

[JIM D.]

When a piston jumps a pin, it can be a bass or chord piston. Always with the note or notes sounding with the bellows in
both directions.