Do you have a Yamaha FC7 expression pedal you could use to check out the circuit? They work ok with the CS-80, but the range is a bit biased compared to the original light-operated unit. That will at least tell you if the sensor in the pedal is dead, or if the sensors in the CS-80 are dead.

Also be aware there are two independent sensor circuits on the CS-80 PRE card, one for the Left output and one for the Right output. So, try the Left and Right output jacks independently using a known-good pedal (like an FC-7).to determine if the sensors in the CS-80 are bad.? Be advised the sensors can "sort of" work and pass just a little bit of?signal. You may be able to hear just a little bit of output from one side and none or a little more from the other. They can pass all of the signal,?none of it, or anywhere in between.

If one or both of the sensors in the CS-80 are dead, replacements are available. I'm not familiar with the pedal sensor as I've never had one to work on. I expect a properly spec'ed?replacement would be available for it as well. It's probably the same as a CS-50/60 aftertouch sensor, but that's just a guess.

On Sat, Sep 3, 2022 at 8:44 PM Gustavo E.E. Grinovero <geegrinovero@...> wrote:

Hello Mathias, in a couple of weeks I will be at the place where it is stored my CS-80.

Then I will be able to take note of the Foot Controller circuit and pass you some information to verify yours.

Hold on.

Have a nice weekend!,

Gustavo.

On 9/3/2022 6:08 AM, Mathias Tjonn wrote:

Hi Gustavo,

?

Thank you for the information! I did open up the pedal and good news: the bulb is working when plugged in and gives off light.

I don't know how to test the photo-resistor, however. Any help appreciated!

...or if the fact that the pedal is not working, means there is something wrong with the CS-80?

?

Any further thoughts much appreciated. Best, Mathias