Distorted/fuzzy sound + random out of tune on XP-80

[Guzman]

-Distorted/fuzzy sound-

I have a Roland XP-80 for about 20 years now. Still working fine. But I've noticed for a few months now that, in most of the sounds, at the end, when in faded out, I hear a distorted noise (fuzzy sound) for a few seconds until it disappears. The longer the sound, or the more reverb it has, the more this noise is heard. Does anyone know what this could be?
I share here a link where you can hear that fuzzy sound. It's at the end of the sound. Best hear it with headphones.

https://drive.google.com/file/d/1dQdXw3 ... share_link


-Random out of tune-

And another problem I have. Sometimes, what I'm playing (or listening to pre-recorded song in the sequencer), the sound starts to go out of tune and vibrates a lot. Looks like the "pitch bend" handle is out of control. And, if I move the handle, the "pitch bend" doesn't work. I send here an example of a sound in which it was out of tune. What could this be?
I share here a link where it shows that problem.

https://drive.google.com/file/d/1Gq22Ri ... share_link