Geeetech

I have a Geeetech Prusa Mk3 pro A printer and the small part failed after 16 months is:

'Click button'- Alain called it many posts prevously
or call it.
'Rheostat' - contol knob / push button
It is in the front part of the power supply / control box that has the emergency stop button, the lcd display, SD card reader and the knob.
Mine says "GTBOX_lcd_board 2015 V1.1"
I can't scroll thruogh menu options.

has anyone had this trouble?

Is there a way to buy just the rheostat? front panel GTBOX_lcd_board? or must I buy a whole new power supply / control box?

I want to know if your printer can print through the USB serial port, so you can confirm whether it is the problem of knob button beside LCD.

yes. it can
The knob and push button are bad and have been going bad since new. How do I get another one?