Hello All,

I decided to build my own 3D printer (Marlin FW, Arduino Mega, Ramps 1.4) and recently purchased a RepRapDiscount Full Graphics Smart Controller to use with it. I have connected it up and uncommented the line of code in Marlin to use it. When I turn on the machine, the LCD screen shows the main landing page (extruder temps and positions). I can press in the button and get to the menu screen, however, once on the menu screen, I cannot scroll through the menu options. Turning the knob takes me back to the main landing/information screen. I assumed that the LCD was potentially faulty and purchased a second one, however, I'm having the same issue.

I have tried:
Multiple cables of differing lengths
Multiple units
Reseating the cable connectors on both the Ramps board and the back of the LCD

After searching both this discussion board and google, I've found a few people with the same issue, however, they never post a solution to the problem. I'm at a loss at this point. Does anyone have any ideas as to how to be able to scroll through the menu options?

mine has two connectors, 1 for screen and the other for sdcard. the button/rotary dial has 2 functions, rotating for menu selection, and pressing for a button.
the rotary functions come through the sd cable. to have full functionality both cables must be plugged in.

Thank you for responding. Yes, both cables are connected. Pressing the knob works as expected, however, I'm still unable to scroll through the menu options.

Its is more likely the LCD converter PCB or the ramps has the hardware issue.

Please forgive my lack of knowledge here. Is the LCD converter PCB the small board connector that comes with the LCD? If so, I've tried more than one of those with the same result. I have not yet tried a new ramps board.

New ramps board fixed the issue. Thank you for your help!