Vintage Synth Repair

Hi, the mystery is over, the keyboard flexible PCB (and much of the 
galvanised chassis) had been corroded by cat urine! I was able to 
bypass the corroded region by scraping off the top plastic layer of 
the PCB with a scalpel to reveal the silver paint below, gluing a 
very flexible wire to the PCB for strain relief, then quickly 
soldering the wire to the paint.

Cheers,

Andrew.

--- In vintagesynthrepair@yahoogroups.com, "aent440" <andrew@...> 
wrote:
>
> Hi Fran,
> 
> Thanks for the quick reply. I think I am going to have to bite the 
> bullet and strip out those offending keys to check that region out. 
> 
> Cheers, 
> 
> Andrew.
> 
> --- In vintagesynthrepair@yahoogroups.com, "narfman96" 
> <narfman96@> wrote:
> >
> > Andrew, The D5 has a membrane style plastic film for key 
contacts. 
> Have 
> > you checked for dirt and/or corrosion between the film layers? I 
> can 
> > look at the D5 in my shop if you need more details. It's been a 
> while 
> > since I was inside it.
> > Let me know, Fran
> > 
> > --- In vintagesynthrepair@yahoogroups.com, "aent440" <andrew@> 
> wrote:
> > >
> > > Hi, the top 5 keys (intermittently) fail to sound on my D5. I 
can 
> > > always see a time multiplexed signal for each key on the main 
> board 
> > and 
> > > can just about see a difference in pulse width when the second 
> > velocity 
> > > contacts come in (but not as pronounced as for the working 
keys). 
> I 
> > > have a paper copy of the service manual but it does not 
describe 
> the 
> > > keyboard. Does anyone have a description or schematic of the 
> keyboard 
> > > operation please? Thanks in advance, Andrew.
> > >
> >
>