Re: Please help, strange movement while printing

Hi,

I tell you how I solved this troubles if it can help...
I have had garbage on the screen so I shortened and shielded cables, it solved screen troubles but then I had the "strange movement while printing" as described by Scubi...

For safety reason, earth AC wire ( the yellow/green one ) is connected to aluminium frame of printer.
Earth is also connected to GND (or 0V ) inside the switching power supply (most switching power supply are not isolating gnd from earth)
My LCD board was hooked on the frame with metallic screws. So ground(0v) of LCD board was connected to ground(0v) of the power supply through the aluminium frame.
But ground(0v) of LCD board was also connected to ground(0v) of the power supply through cable between ramps1.4 board and LCD board.
So I had a big "GROUND LOOP" !!!
I just replaced metallic screws by nylon screws and nylon rings, in order to isolate LCD ground from aluminium frame, and everything works fine now !
I think that noise due to "ground loop" is more important that noise due to unshielded cable.