The origin of this model is China. In my country, I have contacted their factory, but it cannot be solved.
I sent it to the factory by express, but the factory didn't find any problem, nor did It encounter any use problem in the factory, so it is inferred that the indoor temperature is the reason?? They sent it back to me.
Now the same problem is happening again, I strongly recommend Yamaha to do a recall !! Because we have so many users here that their The screen(display) is patterned(Disordered display)