Power off the device and remove the SIM card tray.
Power the device on. Verify the display is clear, touch works, and there are no flickers. Only then close the case. m522-main fpc v1.1
The device fails to recognize the USB cable or charges sporadically. Power off the device and remove the SIM card tray
The specific you're trying to fix (no power, no display, etc.). m522-main fpc v1.1