Do I have a dodgy LCD Display Controller?

Hi all,

New to forums and 3D Printing (but messed with Arduinos for years), but I've made a good start and getting fairly good prints already (at least in my opinion!!). I bought a clone i3 - the Tevo Tarantula, I have got everything setup and started to modify a few things to suit my setup.

One of the things I wanted to do was switch from the standard 2004 LCD to the 12864 Graphics LCD. Through research this seems somewhat straight forward, comment out the old and uncomment the new. All has gone well so far, however I am getting some odd behaviour on the LCD itself.

Everything boots up fine, but after a period of seemingly random time, the 0 point on the screen seems to shift so all the text gets pushed along. I thought this would be a firmware issue given the LCD does actually work and operates as expected. I am running a version of Marlin Community for the Tevo Tarantula. I have also tried with Marlin RC8, and the same issue occurs. Given the 2004 LCD works fine, my thinking is this might be an LCD Controller issue - but its one I haven't seen before.

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After


I have ordered a new one just to be safe (and seeking a refund on this one), but I was hoping to get some expert opinions - perhaps I have missed something in the config files? Config is attached, as are pictures of the issue I am talking about.

Thanks all!!!

I'm beginning to think it is the G8LIB library that is playing up - does anyone know what version I should be using?

It seems to be an unstable display controller changing the picture frame rate or frequencies while warming up. ( it zooms in due to changed frequency )