Marlin shows gibberish

I have ramps 1.4 with marlin installed on my home built printer, I have an endstop for the top and bottom of each axis and have them configured correctly to the correct pins, I have checked each one with pronterface. My printer works as far as I can tell through sending moves through pronterface however my lcd shows total gibberish on the screen. It is a reprap discount full graphic smart controller. I have this configured correctly as far as I can tell in marlin with U8glib installed.
The lcd shows correctly until i want to use it then it just randomly will go from making sense showing what its supposed to then all of a sudden it is total nonsense. The lcd and menu works sometimes and sometimes it does not. I cannot seem to find how to replicate the issue consistently other than looking away for a second and looking back. if I stare at it nothing goes wrong until the moment I glance away.

I apologize if this doesn't make sense, ive literally been banging my head on the wall trying to figure this out.

Mine did the same thing when I went to 1.1.8 Marlin version.

Maybe the ribbon cables need some shielding? Wrap aluminum foil around each of them individually and make sure the foil has good contact to "earth" too.

Edited 1 time(s). Last edit at 02/12/2018 02:34AM by o_lampe.

I tried that and it didn't do it, i grounded the aluminum foil to my chassis and to the grounds of my power cord, and both power supplies in my box. Problem still occurs. I am running the latest version of marlin, the display did work a couple years ago when I used it last as well, i had it in a storage box as i rebuilt my printer and ordered all new electronics for what turned out to be a programming issue. Should I use the old version of marlin?

That's what is called " stable" version in Marlin? Or did you use one of the "release candidates"?

I had similar problems on an A8. In my case the problem was a poor ground connection on the power supply. I managed to fix it by soldering on some ring terminals for all my wiring going to the PS screw block, and tinning the leads going into the screwposts on the printer circuitry.

Quote
Dr_aia
I have ramps 1.4 with marlin installed on my home built printer, I have an endstop for the top and bottom of each axis and have them configured correctly to the correct pins, I have checked each one with pronterface. My printer works as far as I can tell through sending moves through pronterface however my lcd shows total gibberish on the screen. It is a reprap discount full graphic smart controller. I have this configured correctly as far as I can tell in marlin with U8glib installed.
The lcd shows correctly until i want to use it then it just randomly will go from making sense showing what its supposed to then all of a sudden it is total nonsense. The lcd and menu works sometimes and sometimes it does not. I cannot seem to find how to replicate the issue consistently other than looking away for a second and looking back. if I stare at it nothing goes wrong until the moment I glance away.

I apologize if this doesn't make sense, ive literally been banging my head on the wall trying to figure this out.

Had this happen to me all of the time. I re-routed my controller cables to the display card and the problem went away. These RepRap discount ... controller units are pretty poorly designed and highly susceptible to electronic noise. I have yet to find a way to shield them or ground the controller, or whatever - Only routing the ribbon cables through a different area solved my issues.

DLC