Download Android Jelly Bean 4.3 stock firmware for Onda V819 4G LTE Tablet from here or from here.
Firmware： v819_4g-ota-eng.chinachipModel： Onda V819 4G LTE Tablet Image file size: 406 MBPlatform: Intel Z3735EOnda V819 4G LTE Tablet Specs
Model: ONDA V819 4G LTE Quad Core Tablet PC
CPU: Intel Z3735E, Quad Core, 1.8GHz
GPU: Intel HD Graphics
Operation System: Android 4.4
RAM: 1GB (DDR 3)
ROM(Memory): 16GB Nand Flash
Shell Material: Plastic
Screen: Size: 8.0 Inch
Type: Capacitive Screen, IPS
Display: LCD
Resolution: 1280 x 800px
Visible Angle: 178°
Extend Card: Support TF card up to 32GB extended
Camera: Dual camera, front is 2.0 megapixels, back is 5.0 megapixels
ADS HERE !!!