>>51
まとめてこんな感じ

What I meant by "every LEDS Randomly runs on and off" is that all 24 LEDs, from "off" to "12", get on-and-off irregularly (like Christmas ornaments). While
that is happening, the amp doesn't accept any input. An instrument shop guy
who saw this happening tried to reset the machine by pushing three output
buttons, but it didn't help.

This symptom happened three times, and each time I send it for a repair. It is
quite weird that you (and SSL) can't observe this symptom, occurred at both
my home and the shop. If that's the case, it might be because the equipment
was dehumidified in transport. Maybe I could just wait rather than asked for a
repair.

Anyway, I got one more question. You say "however the encoder was not good,
and we changed it" Could you tell me what was wrong with the encoder? Was it
because of rust/corrosion caused by humidity?