I have a guitar multi-effects pedal (a Boss ME-70). Sometimes I have a tone dialed in, and then it randomly changes sound to a very fuzzy / fat tone. When it does so, a number (usually around 90ish) appears on the digit screen.
I can get the original tone back by switching tones, and then switching back again. For example I'm on tone 1, it goes to a fuzzy sound, switch to tone 2 (which is fine), switch back to tone 1 (it's fine).
The frequency of this appears to be random - it can happen a lot e.g. today every few minutes, or just once every ten minutes or so, or less frequent.
I have had this effects pedal for about a year, and I had no problems before a few weeks ago. It's second hand though, I don't know how old.
Two short video examples of this:(happening with a more "metal" tone)
https://youtube.com/shorts/GzBSX2QrJRw (happening with a more "rock" tone - sorry, poorer sound quality)
Any suggestions of how to fix this would be welcome.