Download latest Android KitKat 4.4.2 Stock Firmware for Vido M87 / YuanDao M87 tablet from here or here. Download previous firmware from here. Download Vido / YuanDao firmwares from here.
Update file name: M87-4.4-20150105-V3.10
Archive size: 587 MB
Model: Vido M87 / YuanDao M87 tablet ZZ model
config_version: V1.1.2
Platform: Mediatek MT6592
Project: hv1a_715_yd_m87
ADS HERE !!!