Dropped accordion. Bass part makes sound without pressing button.

[EvKey]

After dropping my accordion, the bass part starts to have sound coming out without me pressing the buttons. This happens both when the bellow is pushed or pulled. I took out the mechanisms, and tried pushing and pulling below with only the valves and there's no sound. But when I put the mechanisms back the sound is back again. I looked at common accordion failure modes but I don't think my problem matches any. The bass mechanisms seem to not have damages, as seen by a novice accordion player like me. I am intrigued by accordion mechanisms and want to try fixing my poor accordion.

• What are the common cause of this problem?
• What are the steps I can do to better diagnose?

Thank you all for your time.

 

[Dingo40]

I'm not skilled enough to offer a definitive diagnosis but I guess something's either bent or dislodged ?

 

[debra]

Diagnosing a failing bass mechanism based on just this description is near impossible. There are just so many ways in which a bass mechanism can fail... The most common failure is a "jumped pin" inside the mechanism. (The piston was pushed and failed to push one of the levers but "jumped" next and beyond it and ended up on the wrong side of the lever it was supposed to push.) This can happen during transport or a fall. (I have one in for repair here that had this but not with a piston but down below deep in the mechanism. It happened during transport in the car.)
But with a fall many more things can go wrong because of the larger impact force. Wood joints may fail for instance, bolted connections may come loose, parts may break, etc. It's not a novice repair job.
Here is a picture of the failure I just had to deal with. In the center of the picture you see a "vertical" shiny rod, that actually pushes the pallet open. Below it (dead center) you see a "hook-like" lever that pushes the vertical rod "open". Where they meet the vertical rod had "jumped" the lever... (The picture is from after the repair.) All of this was hidden deep beneath the larger assembly of the bass mechanism (with the 120 pistons). It would be impossible for a novice to diagnose this problem (even though the fix is then simple).

 

[JIM D.]

You have jumped 1 or more pins on 1 or more of the bass pistons. If you are not familiar with bass machine repair,
you will have to take it to someone for correction. It's a simple process that only involves labor.