Roland FR 7xb, fauly bellow control

[jjj333]

On eBay, I got lucky and won the auction of that FR7xb for only $A1500. Of course at that price, one expects some problems with it. So far everything seems OK, apart from that the bellow only increases the sound volume when I close the bellow; not when I open/pull the bellow.
I have no service manual for it and so I tried my luck by opening the bass part, but there was only the speaker and the bass button wiring so closed it up again.
Thus, it must be that the bellow controller is in the treble part. I already opened the treble part and there too, I see only a speaker and some air holes, which indicates that the bellow control must be in the treble front of the accordion. Thus, to access it I searched in the wrong places.
Now I see how to unscrew the treble grill to get access to the main electronics of the accordion. Hopefully, the bellow control isn't all that complicated. and I can repair it.
Has anyone of you, good people some technical know-how, which would help me to fix the problem?
Besides, I'm a young 82-year accordion music fanatic (from Townsville/ N-Australia) and still interested in everything life has to offer...

 

[Ventura]

the original fr3 and 7 had one sensor for bellows pressure,
with the development of their short lived fr18 diatonic they did
achieve dual sensor tech, and added it to the 7x

so you will likely find actually 2 separate circuit board components/areas
that connect somehow through to the bellows chamber,
one for push one for pull, or seemingly one sensor that is visually hiding
it's flip flop capability..

i am assuming you DiD do a global reset to begin your troubleshooting ?

there is also a run time pressure sensor "balancing" procedure as part of
known troubleshooting, though this has been because of obvious volume
differences on pull vs push, nevertheless you should search the info out and
run the calibration in case it is simply a glitch that set one side to 0 / zero value

good luck

 

[jjj333]

Thank you, Ventura for that, because I'm totally lost about where I have to find it and/ or how the circuit looks. I wished I had the service manual.

 

[SergeRbt]

Hello,
You can get Roland FRx Service Manuals from this site :

404 missing

www.manuals.altervista.org

Bonne journée !

 

[nikolas]

Hi,
you have to recalibrate the bellow's sensor. You can do that by pressing and holding UP and DOWN buttons together before powering on the accordion. After it boots, keep the buttons pressed for another ~5 seconds.

This troubleshooting is added to the Addendum of the 7X Owner's Manual.

Hope it helps.

 

[SergeRbt]

Hello,
Good point Nikolas !

and for memory, Bellows calibration has always to be done with bellows closed (not moving).

Have a nice day !
Wishing all of you a Happy New Year !

Serge