LCD12864 on old UM 1.5.4

[tecnao 0]

Hello,

I wanted to improve my precious UM printer running with its 1.5.4 board. As the Ultipanel was too expensive for me, I bought a cheap LCD12864 LCD module with SD card from greeetech. It comes with its two 10 pins cables to link to the UM ext pin board. Unfortunately, nothing works as expected . I already spent 2 days through different forums to find a solution, no way.

I tried all these methods :

Update marlin V1 with u8glib (and modify config.h as advised here :http://www.geeetech.com/forum/viewtopic.php?f=23&t=17040) and send to UM -> Nothing lights on no beeps.

Reverse the cable as advised here : https://ultimaker.com/en/community/4614-question-about-lcd-controller-substitute.

+ update marlin RC with u8glib -> Backlight ok and beep. But nothing on the LCD.

Add a direct 12V line to avoid the USB line as explained here :http://wiki.ultimaker.com/File:Patching_old_electronics_to_selfpowered.png

I tried so many combinations that I don't remember all of them, but never succeed to have an autonomous UM as required. I even had one which which has burnt the remaining PLA in the head up to smoke and bubbles, using bultimaker (probably with wrong parameters) : https://bultimaker.bulles.eu/

Anyway, your help would be highly appreciated, as the usb port is full of contact failures so the autonomous option will allow to use this vintage printer for a few more years.

Thanks in advance.