VIVO Y21T : LCD BACKLIGHT WAYS, DISPLAY LCD WAYS & TOUCHSCREEN WAYS 

LCD, LIGHT, BACKLIGHT, DISPLAY, CAMERA, AUDIO, USB, CHARGING, USB, FINGERPRINT, HEADSET, KEY BUTTON, ISP PINOUT, PMU INPUT OUTPUT, POWERBOOT, CELLULAR NETWORK, SDCARD, SIMCARD, WIFI, BLUETOOTH, GPS, SCHEMATIC, SOLUTION, PROBLEM, JALUR, WAYS, SKEMA