Vintage Synth Repair

Hi all.

I was given a Roland U-20 that seems to have some keyboard problems. A
lot of the keys don't sound at all, or are at half volume. If you
knock the keyboard, or the stand even, sometime you the key will start
to sound. To me, it sound like there is corrosion or something on the
contacts. Is this something that I remedy myself? I am hoping that the
mechanical aspects of the Roland keyboards are close enough to others
that someone can answer me.

I took the bottom off the keyboard but that is as far as I have
gotten, as of yet I cannot see how to remove the actual key assembly.
I have a Korg DW8000 that had 2 keys malfunctioning and I was able to
get that working, I am hoping that this will be repairable by me also.

I hooked it up to another keyboard via MIDI and all worked great, so
pretty much the keys are muckered up.  The only other problems I have
found is the bank 6 button does not respond and when I try to access
PCM cards, it can't find them.  Have to wait to see if this is a card
problem or more bad contacts.

Thanks all

Thanks for your help

Roland U-20

( Posted by: "LonePiper")

    Roland U-20... If you knock the keyboard, or the stand even,
sometime you the key will start to sound. To me, it sound like there
is corrosion or something on the
    contacts... the bank 6 button does not respond and when I try to
access PCM cards, it can't find them. 

    (Reply)
       ---Sounds like it took a beer spill on a gig one night.
       If gaining access to the innards is the problem, I can't help
you - I haven't had that many Rolands to dissect. But I do know I've
been able to get this trick to fly on an EMAX keyboard, and its
illegitimate cousin badged with a Baldwin logo: I take a 4"x1/2" strip
of fairly coarse paper (not abrasive), get it moistened with a
compound like Caig's DeOxit or just a common tuner cleaner; hold it
between the key contacts in question, press down on the key or button
and drag the strip thru the closed contacts 2 or 3 times.
       Similar chemical treatment is done with a toothpick or
toothbrush inside Molex plugs (or other quick-connect devices) that
connect the keyboard or control board to the main PC board.
       Don't know if this is helpful or obvious, but either way, good
luck.

    AP

--- In vintagesynthrepair@yahoogroups.com, "rollingvalleyradio"
<rollingvalleyradio@...> wrote:
>
> Roland U-20
>

Lots of times the ribbon cabling starts to crack etc.  Roland has a
retro I think for it still or maybe it's only retro'd for the Rhodes
660 that I did a while back.  Same idea but different interconnect
setup.   -Bob

Hi,
The problem here can be that the pink glue that holds in the weights
under the keys themselves is melting and this is a mess. It will melt
onto the rubber contacts and circuit boards "upper and lower". If that
is what is happening and if you can find a receipt of the original
purchase then you can have it replace by a service center with a free
assembly you pay labor. Good luck finding a receipt.
To remove the melted glue I have heard of using "freeze spray" that
the spray used to cool down circuits for troubleshooting. This will
harden the glue and make it easy to take off the keys and board. The
rubber contacts will need to be replace more likely. As for the panel
switches I found that by removing the circuits boards completely and
then cleaning off the dust then spraying a small amount of lubricant
such as D-oxit 5 onto each TAC switch and then gently depressing and
releasing continuously so that  the switch is cleaned out. Test the
switch with a multi meter for continuity, making sure that when
depress you have Zero Ohms of resistance.

Good Luck!
Eli
--- In vintagesynthrepair@yahoogroups.com, "LonePiper"
<maccrimmon@...> wrote:

>
> Hi all.
> 
> I was given a Roland U-20 that seems to have some keyboard problems. A
> lot of the keys don't sound at all, or are at half volume. If you
> knock the keyboard, or the stand even, sometime you the key will start
> to sound. To me, it sound like there is corrosion or something on the
> contacts. Is this something that I remedy myself? I am hoping that the
> mechanical aspects of the Roland keyboards are close enough to others
> that someone can answer me.
> 
> I took the bottom off the keyboard but that is as far as I have
> gotten, as of yet I cannot see how to remove the actual key assembly.
> I have a Korg DW8000 that had 2 keys malfunctioning and I was able to
> get that working, I am hoping that this will be repairable by me also.
> 
> I hooked it up to another keyboard via MIDI and all worked great, so
> pretty much the keys are muckered up.  The only other problems I have
> found is the bank 6 button does not respond and when I try to access
> PCM cards, it can't find them.  Have to wait to see if this is a card
> problem or more bad contacts.
> 
> Thanks all
> 
> Thanks for your help
>

Hi
Thanks for the response.  I eventually tore the keyboard apart over
the course of a week and finally got the keyboard subsystem out.  What
a pain!  To clean the contacts every key had to be removed.  I didn't
see the glue problem that you mentioned but knowing that now, I may
tear into everything again and see if I can cover the glue with
something like a squirt of silicon to keep it in place.

I did get the keys working again.  One or two sometimes don't respond
but overall it was a success.   Thanks for the tip on the buttons.  I
will work on them soon as there are three or four that are squirrely.

Here is a link to FlickR where I posted the repair pics.

http://www.flickr.com/photos/lonepiper/sets/72157612295420994/

 



--- In vintagesynthrepair@yahoogroups.com, "Eli Corral"
<austinkeyboards@...> wrote:

>
> Hi,
> The problem here can be that the pink glue that holds in the weights
> under the keys themselves is melting and this is a mess. It will melt
> onto the rubber contacts and circuit boards "upper and lower". If that
> is what is happening and if you can find a receipt of the original
> purchase then you can have it replace by a service center with a free
> assembly you pay labor. Good luck finding a receipt.
> To remove the melted glue I have heard of using "freeze spray" that
> the spray used to cool down circuits for troubleshooting. This will
> harden the glue and make it easy to take off the keys and board. The
> rubber contacts will need to be replace more likely. As for the panel
> switches I found that by removing the circuits boards completely and
> then cleaning off the dust then spraying a small amount of lubricant
> such as D-oxit 5 onto each TAC switch and then gently depressing and
> releasing continuously so that  the switch is cleaned out. Test the
> switch with a multi meter for continuity, making sure that when
> depress you have Zero Ohms of resistance.
> 
> Good Luck!
> Eli
> --- In vintagesynthrepair@yahoogroups.com, "LonePiper"
> <maccrimmon@> wrote:
> >
> > Hi all.
> > 
> > I was given a Roland U-20 that seems to have some keyboard problems. A
> > lot of the keys don't sound at all, or are at half volume. If you
> > knock the keyboard, or the stand even, sometime you the key will start
> > to sound. To me, it sound like there is corrosion or something on the
> > contacts. Is this something that I remedy myself? I am hoping that the
> > mechanical aspects of the Roland keyboards are close enough to others
> > that someone can answer me.
> > 
> > I took the bottom off the keyboard but that is as far as I have
> > gotten, as of yet I cannot see how to remove the actual key assembly.
> > I have a Korg DW8000 that had 2 keys malfunctioning and I was able to
> > get that working, I am hoping that this will be repairable by me also.
> > 
> > I hooked it up to another keyboard via MIDI and all worked great, so
> > pretty much the keys are muckered up.  The only other problems I have
> > found is the bank 6 button does not respond and when I try to access
> > PCM cards, it can't find them.  Have to wait to see if this is a card
> > problem or more bad contacts.
> > 
> > Thanks all
> > 
> > Thanks for your help
> >
>