Yamaha P515 with FC4A pedal issue. Pedal keeps swapping polarity and stops working altogether. Any experience with such problems? Will it turn out to be an issue with the pedal or with the keyboard?
How do you know that the polarity is changing at random intervals?
These are both Yamaha products, so the pedal should, as you know, work fine without using one of the "trick" kludges to swap polarity.
I would bet it's the pedal. Loose connection somewhere inside, maybe part of the cable is shorting inside.
If only due to an optimistic nature, in that if it's not the pedal, you'd have to deep dive into the keyboard, or, more likely, pay someone to do it, which would be a hassle. And if not impossible, it would take a long time to try swapping new components to the motherboard, probably starting with the 1/4" receptacle for the pedal connecting to the motherboard (or however it's attached), which is not soldering for beginners.
/* Oh, about experience with these problems, I did have to swap polarity on one pedal+keyboard that were incompatible, using the low-tech kludge of putting a pair of interlocking male/female 1/4" TRS adapters in the chain.
I do have that same Yamaha pedal, used with a Yamaha keyboard, and I haven't had that problem. The pedal itself does not appear to be made to be disassembled, so you may have to physically crack open the plastic housing. You could put a new cable on it, if you feel like soldering and putting shrink tubes on the exposed wires.
I think you should test a new pedal on it, and buy from someplace where you have the option to return it without a restocking fee if it doesn't solve the problem.
So, I really don't know, just running through some options.
*/