Vintage Synth Repair

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
>