Weather Box - LCD12864 blue screen

1537108674

Hi, I bought a starter kit, the Adeept indoor environment weather box and after run all the lessons and check each one of my sensors i conclude that my screen is not working properly.  all the sensors and programming are performing as expected, but the screen just return a blue screen and even the test of LCD12864 does nothing on screen.  
How to fix the screen?

1501915115

First check if the circuit connection of LCD12864 is correct.
Second: Check if there is a potentiometer on the back of the LCD12864 module, and if so, rotate the potentiometer. If there is no potentiometer, please refer to this blog for an experiment：http://www.adeept.com/Blog/?p=251