1.1, Check the log, (On MTK platform keyword “LCMAutoDetect”) to ensure that the LCD Display driver is loaded successfully.
1.2, With an oscilloscope to view DVDD, (AVDD, VGH, VGL, VCOM) (some interfaces of the screen built-in these voltages) the voltage value of each group and the power-up timing is in line with the specifications. If the voltage value is not correct, you need to check the hardware schematic to analyze the voltage source. You can find hardware to assist in the analysis.
1.3. Use an oscilloscope to check whether the reset pin pull-up timing meets the requirements of the specification. If it is not pulled up, you can check the hardware schematic to make sure the GPIO configuration is correct. If the pull-up timing is not correct, you can do the corresponding delay and repeated pull-up operation in the driver.
1.4, Check the hardware schematic to ensure that the backlight enable pin GPIO configuration is correct.
1.5, Use an oscilloscope to see if there is a differential signal of the image, so far the LCD should be able to light up normally.
Above is about LCD lighting steps — From Sinocrystal — Display Expert – Stable & Reliable