Flickering Graphic Smart Controller

Hey all, I’m in the process of pulling together my first MPCNC build–which has certainly been a lot of fun, and learning experience so far, though I’ve definitely got a ways to go :slight_smile:

So far, the actual process has been relatively uneventful in that nothing has gone awry; I’ve printed the parts, built a workbench, assembled the pieces, run the wires, connected the stepper motors and got Repetier Host installed and recognizing the board. Unfortunately, while working through the process, I noticed that the Graphic Smart Controller doesn’t work (or at least doesn’t appear to) all I get is a flickering white screen and a clicking noise when the ramps board is powered on.

The issue appears somewhat similar to one that was posted on the forums near the end of January, https://www.v1engineering.com/forum/topic/lcd-flickering-white-screen/, though the issue does not resolve/clear up when USB is plugged in. Also, here’s a link to a short recording I have of the issue I’m experiencing–hopefully it’s enough to help illustrate my issue. I’d appreciate any/all assistance anyone may have!

Also, and as a bit of reference, I purchased my parts via the bundle with the upgraded 30A power supply from the site so there shouldn’t be any “weirdness” introduced by dicey components. Hopefully this is a minor hiccup.

Show us pictures of the connections between the display and the RAMPS. Also, are there any bent to the side pins between the Arduino and RAMPS?

I’ve attached photos showing the the ramps, mega and display boards. As you can see in the the one photo below, the outer most pin (top right with the board oriented with power on left) on the ramps board appears slightly bent, though I checked and was able to determine that the pin was not bent/incorrectly inserted into the display board. Additionally, I checked each of the pins on the ramps to ensure that they to were not bent, and they were in perfect working order; no bent pins. I had hoped that the unseating and reseating each of the board pins after my review would in some way resolve the issue (long shot I know), unfortunately–and not surprisingly–it didn’t work and the screen is still flickering and making the audible clicking noise.

Maybe you will see something I missed though so do feel free to let me know if you happen to see anything in the pictures!

One of your cables is backwards.
Google Photos

Barry, looks like you may have identified something I missed. I reviewed my mpcnc wiring setup and confirmed that while I installed my cables correctly the actual connectors on the display board appear to be flipped. I’ve attached a picture of the board connections on my own board along with a partial screenshot of the connectors of the board from the mpcnc store page. Can’t confirm that this is the source of my issue, but it’s looking to be a step in the right direction.



Yep, there’s your problem! Should be able to just cut a notch with an exacto knife, or something similar. Those kids soldering these things up for 2 cents a piece don’t have time to check this stuff! :wink:

Thanks, worked like a charm! The screen is up and running without issue and I can control the stepper motors. I appreciate everyone’s feedback and help with this!


Well that is a new one. Sorry about that, what a crazy issue. Thanks for the help fellas.

Yes, certainly a weird issue, but easy enough to fix. Thanks again guys, really appreciate it!

At least this display has tabs. The one on my printer doesn’t, so you can plug them in any direction you want!