LCD 12864 not working right

Hi,
I got myself a new display for my Hephestos. I'm running Marlin RC8 with Octoprint and I had no problems with the standard Hephestos LCD.

The new one is the LCD 12864 (full graphic display). I enabled it in the firmware and it worked.

Some minutes after the printer is powered on the display acts weird (see picture attached).

Do I have a broken display or is it a software problem?

Check that both ends of the ribbon cable/cables are fully home. You have the screen in a separate mount so it's easy to pull a cable.

Hi,

I have a different LCD but same type of problem (see attached, the display seems to be worse than yours). I'm running Marlin 1.1.0 RC8 and the cable are connected right.
When I press the display controller button, the screen displays right again, and after a few seconds (variable) it goes back to displaying some sort of garbage, so I do not understand where it can came from :/

Any help please ?

thank you

It is just possible that you may be getting a static electricity build-up on the screen board. This has been known to be a cause of this problem. Unfortunately I don't know a solution if this is the case.