Yamaha CS80

Thorsten P\ufffdrschke wrote:
> Hello David
>
> Thank you very much for your quick answer.
> I wanted to know which pcb (KAS, TKC, TSB1, eg.) you choosed to start with?
> Did you also overhaul the power supply and if which parts besides the cap. 
> did you changed.
>
>   
I don't remember what order I did the boards in.  I did, however, do one 
board at a time and made sure it was still working before I did the next 
board. I did have a couple of solder bridges that took some time to 
find, and generated really weird symptoms.  You need to have a decent 
multi-meter and simple oscilloscope, the schematics (mostly available 
online - see Links), and an understanding of some digital and analog 
electronics, because something will go wrong when removing/replacing 
over a hundred 14 and 16 pin chips!

There's tons of detailed pictures I put on the site (Photos > CS80 
renovation) as I did the work.  The only thing on the power supply was 
replacing all the caps (other than calibrating it).  All 4000-series 
CMOS chips were removed, sockets soldered in, bypass caps added, and new 
chips put in.  I also added larger caps for each board.  I basically 
followed Crow's website.  The biggest help was buying a used 
de-soldering station.  It would have been crazy to try it with just a 
spring-loaded solder remover.  When I was done, I sold it (to the owner 
of the Yahoo oldsynths group).

 David