1. If you press the power button, there is no response, please confirm whether the battery has electricity, pull out the battery and plug in the power adapter to see if there is a red LED indication; check if the boot button switch (SWP) is invalid and whether the DC/DC output is normal.
2. If the battery is not fully charged, if there is no indication of charging, check whether the charging IC is normal, and whether the terminal power port and battery outlet are loose;
3, plug in the battery to connect the USB cable to the computer, re-update the kernel software, confirm the programming module kernel is normal, if the normal boot; boot screen but can not enter the system, check the power button is top not release, if the outside is still normal Constantly restart and replace the module; there is no screen to see if the work light and backlight are on, and the backlight is not on. Check the backlight circuit. Check if the LCD peripheral voltage (AVDD: 9.6V, VGH: 18V, VGL: -8V, VCOM: 3V) is normal. Check the screen connection and change the screen to see if the screen is damaged.
4. Write failure Check if the module DCIN port has 5V voltage, VBAT voltage is 4V, VDD_IO28 voltage is 2.8V, VDD_IO18 voltage is 1.8V, VDD_HUB voltage is 5V, voltage abnormalities check related peripheral circuits.
5. If the voltage of each channel in the programming mode is normal and the USB connection is not connected, check whether the SGM7227 (U1) and the peripheral connection are normal, and the OTGID_CTL should be low; if the peripheral is normal, the USB still cannot be connected or the programming will fail. , After troubleshooting the computer, reheating with hot air is still ineffective. Replace the wireless module.
6, press and hold the power button normal boot, a release will power off: This situation can reburn the kernel to try it.