Yamaha SY-55
This time a Yamaha SY-55 came in for repair. I was supposed to replace only the CR2032 battery that maintains the RAM memory. However, quite soon the owner asked me to additionally check all the function buttons, as in his opinion some of them were working very hard.
This is a fairly typical fault in many decades-old devices — not only synthesizers — where the contact elements are cheap TACT-type microswitches. In such a case, it was necessary to replace all 36 microswitches, which required completely disassembling the unit, since the circuit board with these components is located right behind the front panel. As a result, the whole repair became much more complicated and took a bit more time.
Additionally, I also replaced two slider potentiometers responsible for Master Volume and Data Entry, as in an instrument of this age I consider it clearly advisable. Thus, the instrument returned in excellent condition.
