# New Mini LCD not working

**URL:** <https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053>\
**Category:** LulzBot Mini\
**Created:** [March 13, 2020, 5:22pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053 "2020-03-13T17:22:40Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Iggy](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/iggy/32/10012_2.png) [@Iggy](https://forum.lulzbot.com/u/Iggy)\
**Post date:** [March 13, 2020, 5:22pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/1 "2020-03-13T17:22:40Z")

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I bought a new LCD for my mini, but I cannot get it to work. Here’s what I have done.

- Checked the board version Mini Rambo 1.3a
- Flashed to current firmware with LCD checked multiple times using cura 3.6.20 and 3.6.21
- Removed LCD and tested on another Mini to make sure it’s working
- Checked continuity on cable ribbons
- Reversed ribbons

A few things to note, the printer works fine uploads and prints 100%. When the LCD is connected via both ribbon cables, the USB connection does not work. If I unplug one ribbon, it does work and I can connect octoprint.

Any other ideas? I’ve been searching online and can’t get through to support to see if they have any other ideas.

\*Edit: my post got marked as spam for some reason so I’m adding this to unlock it.

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**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.lulzbot.com/u/Jonathan)\
**Post date:** [March 13, 2020, 5:49pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/2 "2020-03-13T17:49:13Z")

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Can you post the link to the the LCD you bought?

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**Author:** ![Iggy](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/iggy/32/10012_2.png) [@Iggy](https://forum.lulzbot.com/u/Iggy)\
**Post date:** [March 13, 2020, 6:22pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/3 "2020-03-13T18:22:13Z")

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> **[LulzBot Mini Graphical LCD Controller](https://www.lulzbot.com/store/accessories/lulzbot-mini-graphical-lcd-controller)**
>
> With the LulzBot Mini Graphical LCD Controller, an easy-to-use digital interface that attaches to the frame of your LulzBot Mini, you can untether your creativity and take it wherever it's most convenient.

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**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.lulzbot.com/u/Jonathan)\
**Post date:** [March 13, 2020, 6:33pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/4 "2020-03-13T18:33:04Z")

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That’s odd, if any LCD worked I’d expect it to be that one. I think you already did this when you flashed the new firmware, but you could try resetting the EEPROM. If you have any settings like your Z Offset, be sure to write that down first. Just use these two commands and it will reset the EEPROM…

```auto
M502 ; reset! 
M500 ; saved!! 

```

…then restart your printer.

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<div class="post-metadata">

**Author:** ![Iggy](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/iggy/32/10012_2.png) [@Iggy](https://forum.lulzbot.com/u/Iggy)\
**Post date:** [March 13, 2020, 6:35pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/5 "2020-03-13T18:35:33Z")

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I can’t connect to the printer when the LCD is plugged into the board.

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**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.lulzbot.com/u/Jonathan)\
**Post date:** [March 13, 2020, 6:37pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/6 "2020-03-13T18:37:22Z")

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Is the SD Card plugged into the lcd by any chance?

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<div class="post-metadata">

**Author:** ![Iggy](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/iggy/32/10012_2.png) [@Iggy](https://forum.lulzbot.com/u/Iggy)\
**Post date:** [March 13, 2020, 7:06pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/7 "2020-03-13T19:06:06Z")

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Yeah, I’ve tried both inserted and not, with the same results.

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**Author:** ![Iggy](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/iggy/32/10012_2.png) [@Iggy](https://forum.lulzbot.com/u/Iggy)\
**Post date:** [May 13, 2020, 10:02pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/9 "2020-05-13T22:02:10Z")

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I finally figured out this issue! After trying literally everything I could I finally broke down a new board. When I got it I was till getting the same error. $95 later and now having two Rambo boards later I was no where close to solving the problem.

Since I had plugged in the new LCD to my other printer and it worked, I know there was something wrong. Using a Rambo board with loaded firmware and nothing but power and the LCD attached I went to trouble shoot again.

I had tested continuity on the ribbon cables, but I suspected they were the issue. After searching for pictures of the ribbon cables I saw that the ends of 1 of the two ribbon cables didn’t match up. I took the end connectors apart and reversed the ribbon direction. Sure enough, that was the problem! The LCD was working great.

So the problem was just a badly wired cable from the factory. At least I have a spare rambo board. Maybe I’ll make a new printer just for it so it doesn’t go to waste.

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**Author:** ![mdivancic](https://avatars.discourse-cdn.com/v4/letter/m/0ea827/32.png) [@mdivancic](https://forum.lulzbot.com/u/mdivancic)\
**Post date:** [July 18, 2021, 3:09pm UTC](https://forum.lulzbot.com/t/new-mini-lcd-not-working/21053/10 "2021-07-18T15:09:18Z")

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Iggi:

Thanks for this post! I to had the same problem with the cables being wired backwards from the factory. Never would have figured this out myself. Mine were wired wrong on the LCD end.

Thanks again!  
Mike
