1.1. Check the log to make sure the LCD display driver is loaded successfully.
1.2. Use an oscilloscope to see if the voltage values and power-up times for each group of DVDD, (AVDD, VGH, VGL, VCOM) (these voltages are built into the LCD display for some interfaces) are within specification. If the voltage values are incorrect, you will need to check the hardware schematic to analyze the voltage sources. You can find hardware to assist in the analysis.
1.3. Use an oscilloscope to check that the pull-up timing of the reset pin is as required by the specification. If there is no pull-up, you can check the hardware schematic to make sure the GPIO is configured correctly. If the pull-up timing is incorrect, you can do the appropriate delay and repeat pull-up operation in the driver.
1.4, Check the hardware schematic to make sure the GPIO configuration of the backlight enable pin is correct.
1.5. Use an oscilloscope to see if there is a differential signal for the image to this pointLCD displayIt should light up fine.