12864 LCD Missing Pixels

Hi There,

I am in the process of building an MP3DP and at the moment I am testing all of my components to get things in a working state and to understand how all of this actually works.
Last night I was testing the LCD, which is a Full Graphic Smart Controller, and on power on I noted that it had two rows of pixels separated by a 3-pixel gap. I didn’t think anything of it until the firmware was loaded and I was missing detail.

My setup is a TriGorilla ramps board running marlin 1.1.9 and I have set:

On startup, my LCD looks like This
Once running it looks like This

It doesn’t appear to be broken pixels as the ones that are not displaying move around, you can see some are active in the second pic, but that may just be my wishful thinking.

Just wondering if anyone else here has seen behavior like this, any ideas welcome, I am completely new to this so its likely something I have mucked up.



Your software is good. Your connections are good, or it wouldn’t have gotten that far. It must be hardware.

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Well, that sucks. I will have to see if I can find a replacement that doesn’t take 3 weeks to ship! My patience for parts arriving is at an all-time low.

It will have to be fine for now.

Time to move on and test all the steppers and extruder motors.


OK, so a little more playing (testing) and I was had a last minute thought, maybe the mounting screws and standoffs are putting pressure on the LCD…
I backed off the screws by a half a turn and luck had it this was exactly what was going on. I have all pixels and the display is working as expected.

Lesson learned, keep playing until you have completely broken it;) Or it works properly…


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Sometimes you can fix that by bending the little black tabs a little tighter. It can make a better connection, sometimes. Other than looking funky you are not missing any vital info though.

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Ah good to know, thanks for that tip. I think to twist those I would have to de-solder the pins to separate the LCD and Control boards. If it comes back and I can’t solve it that will be the next thing I try.

Lucky nothing major was missing, it just annoyed my inner pedant…

You can bend it up a bit and get a flat head in there if you are feeling adventurous.

I will give that a go.