LCD Display problems!

Greetings, fellow maker nerds! Please help! I have a new 3D printer from China and I can't get the Reprap Discount Full Graphic Smart Controller display to show anything beyond the start screen. None of the other menus work when I push the button. The only thing that happens when I turn the knob is the FR number goes up or down. I have a mega2560 CPU, RAMPS 1.3 and RepRapDiscount Full Graphic Smart Controller. Configured with Marlin... I installed U8glib. Also, and I'm not sure if this means anything, the home screen display keeps flickering back and forth between a question mark and the letters X,Y and Z, which all have values of 0.

I am using Repetier Host as a controller. When I try to press Home for X or Y, it goes in a random direction and the motors make noise. I followed directions on this wiki to set it up, but I'm not confident that the X,Y,Z positions are working properly. Not sure if this has anything to do with the LCD display problem or if these are 2 separate issues...

Advice, anyone... PLEASE!

Blinking X,Y Z indicate the axis has not been homed.

Here is my config.h copy/pasted into Word. I removed a lot of things that I didn't change and highlighted the areas I configured. Any help would be greatly appreciated. I'll send a virtual case of beer to anyone who can assist!

The display only shows the full menu, after you've homed the printer. That's what Dust wanted to say, I'm sure...

As Dust and O_Lamp have said, the display is likely not your issue at all.

You need to work out your endstops, motor directions etc and get each axis to home properly before you can look at your display.

Connect to a PC and use pronterface or as you have stated your on Repetier Host that and work on your setup, if your display does not work, deal with it after all your movement issues are in order.

One axis at a time one issue at a time

Edited 2 time(s). Last edit at 02/19/2018 07:35PM by JustSumGuy.

I have recalibrated X, Y, Z and the display is still flashing. It homes properly.

Ok... No more flashing. Still no menus other than home screen that shows X,Y,Z values and temperatures.

I tried a 1st print, disregarding the LCD display problems... The 1st layer of Benchy came out just fine but then the extruder raised up far too much on Z and started spitting spaghetti at me. I tried Slic3r and Cura. Layer height 0.2.

This line should not be enabled with your display type

#define DOGLCD // Full graphics display

you just need this one as it is
#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER

I tried compiling without the DOGLCD and #define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER active... Still nothing past home menu. Maybe I need to go into config.adv.h or Conditionals_LCD.h? I've look in there but haven't made any changes...

show us your current full configuration.h file plz.

Should maybe ask this in the marlin group btw, I don't know if roxy or other marlin dev's that surf that group look at this one.

sounds like your encoder button simply isnt working, ie is a hardware issue.

code says

#define BTN_ENC 35

so its on pin D35

Check out all soldering related to D35, on the display, the breakout board and the ramps and the mega...