Model cycles screen damage

When I use the knob, similar garbled characters appear. If I immediately restart, the screen turns white, with an additional B appearing in the bottom left corner

Any one knows what happen to it? I checked the ribbon cable and it seems normal

have you run a system test

oh I never tried that.what is that?

With the machine switched off, hold down FUNC and switch it back on. The screen should display some sort of test mode/give you options to choose to run some simple diagnostics. at least it does with the other machines, I assume its the same with the models

thank u! I’ll try that