Vintage Synth Repair

I don't believe the U-20 is powerful enough to to have key assignments that will exclude certain zones of the keyboard. You might try a removing the battery for an hour (there is no ROM reset) or so but I still don't think that will help.

First I would check the key contact rubbers under the keys in the keyboard first. They are subject to years of dust and anything that may get spilled on the keys. They are also known to fail. Look around on the web and see if you can find some pics or maybe even a procedure detailing the ins and outs of removing the keys and fixing the contacts. Any D-10, D-20, D-50 even the newer PCR-30 or 50 should be very similar.

I recently rebuilt an Edirol PCR-30 from parts I ordered from Roland US so there is hope for parts if you need them. If you need more help tell us what you found and we will be glad to glad to help if we can.
 
Good luck,  Fran  (and no not the little mouse in my pocket... the rest of the members here at VSR.) 

--- In vintagesynthrepair@yahoogroups.com, "colin butterfield" <cjbutterfield@...> wrote:
>
> Hi Noel,connected it via midi to my yamaha and the yammy will play the U20 but U20 won't play the Yam,just top & bottom note so seems like the keyboard.All the keys play freely.I can understand all octaves of certain notes not playing as keyboards  are usually addressed as a matrix,but all notes in between has me stumped.Any other ideas gratefully accepted.Colin.
>   ----- Original Message ----- 
>   From: Noel Buhagiar 
>   To: vintagesynthrepair@yahoogroups.com 
>   Sent: Monday, August 08, 2011 10:31 PM
>   Subject: Re: [vintagesynthrepair] roland U20
> 
> 
>     
> 
> 
> 
>   Hi Colin,
>   You could try and connect it to another synth using MIDI IN-OUT and see if it plays ok.
>   If it does, problem could be a bad keyboard and then you’ll take it from there.
>   Old U-20s were known for the sticky-keys problem; are the keys free when played?
>   Hope that helps & keep us posted
>   Regards,
>   Noel
> 
>     
>   Hi, I have an old Roland U20 keyboard,when powered up,only the bottom and the top keys on the keyboard work,all in between do not produce a note.Everything else seems fine,any ideas?? Cheers Colin
>