The LCD screens are used in many devices. Do you know what the LCD lighting steps are? Here's how to light up the LCDs in five steps.
Step 1: check that the log, (MTK platform keyword is "LCMAutoDetect") to ensure that the LCD driver loads successfully.
Step 2: use an oscilloscope to check whether the voltage values and power-up timing of each group of DVDD, (AVDD, VGH, VGL, VCOM) (interfaces with these voltages are built into the screen of some interfaces) meet the requirements of the specification. If the voltage value is wrong, you need to check the hardware schematic to analyze the source of the voltage. You can get hardware to assist in the analysis.
Step 3: use an oscilloscope to check whether the reset foot pulls up the timing to meet the requirements of the specification. If it is not pulled up, you can check the hardware schematic to make sure that the GPIO is configured correctly. If the pull-up timing is not correct, you can do the corresponding delay and repeated pull-up operation in the drive.
Step 4: check the hardware schematic to make sure the GPIO of the backlit enable foot is configured correctly.
The last step: use the oscilloscope to check whether there is a differential signal of the image, so that the LCD screens should be able to light up normally.