ESD causing problems with LCD


I have a 20x4 LCD (purchased here: as part of my Arduino based project.

It is mounted in an aluminum project box which has subsequently been painted. All works fine until I touch the lid of the box (where the LCD is mounted) after any kind of static buildup. This causes the display to either blank or display garbled characters. Powering the device on and off again fixes the issue.

The outside casing of the LCD is metal and is in direct contact with the project case, there are no other contact points. This issue never came up before mounting, but I am not sure if that is just a coincidence or not. I have tried connecting the case to the circuit ground with no result. The problem only seems to occur when touching the lid somewhat near the LCD.

Before I attempt to de-superglue the LCD, I was hoping someone with more experience could comment on a cause for this or a solution :)

Did you connect en and rw pins to something or did you leave then disconnected?

liudr: Did you connect en and rw pins to something or did you leave then disconnected?

You may need some more sleep. How could it "work fine" before touching the lid if these pins were not connected.


Yes, all pins are connected, except for DB0-DB3 as I am using 4bit mode.

Here is a video of the problem occurring. It will do this 100% of the time unless I have grounded myself first. I can live with it if it's just a very sensitive LCD (the manual claims that just peeling off the protective plastic is enough static to corrupt the display) but I would like to know if this is normal or if there is something I can do to fix it :)