Zumo32U4 LCD not working

Hi. I have 30 Zumo32U4.
LCD display is not working in two of them.
I have exchanged the display with other Zumo32U4 and the problem follows the LCD display.
I mean, the robots are OK, but the display not.
Do you have any hint on how to fix the problem?

Thank you,

Hello, Rafael.

Have those LCDs ever worked for you? If you got kit versions of the Zumo, could you post pictures of the soldering on the displays? We have encountered LCDs that seemed to have a loose internal connection. Could you try pushing on the boarder of the LCD’s black bezel to make sure the contacts inside the LCD are properly engaged?