12864 LCD Display Corruption

Examples of Issue

Hardware Issues

This is most commonly caused by poor voltage going to the board CPU. The Ender 3 S1 and Ender 5 S1 boards are known to have 3.3V Rail issues. Test the voltage going to your CPU to make sure it has the proper 3.3V (for 32bit CPUs) or 5V (for 8bit CPUs) going to it. If your board is off by 10% or more, it is defective and will need to be repaired/replaced.

Videos showing this issue on the Ender 5 S1 Board and its 3.3V Rail

Firmware Adjustments

Paste the below lines in your Configuration.h file, recompile, and upload to your board.

#define ST7920_DELAY_1 DELAY_NS(0)
#define ST7920_DELAY_2 DELAY_NS(250)
#define ST7920_DELAY_3 DELAY_NS(250)

Other Suggestions

• Use a shorter cable
• Wrap cable in Faraday cloth tape
• Ensure printer ground pin on AC receptacle to chassis is 0.2 ohms or less
• Check cable for issues/wear-and-tear/improper connection/loose connection
• Remove sources of EMI/move the board and display way from the printer