Download Assistant AP-804 official stock firmware from the link here, and follow the provided flashing instructions to learn how to flash the stock rom.
If you notice that any of the links provided below is broken or doesn’t work, please post in comments section so we fix and update it ASAP.
File Name: FW_804_AP_sn551303_USSDfix.zip
Size: 308 MB
Firmware – Download
How to flash
After downloading the firmware you wish to flash on your Assistant tablet, click here to download the Flashtool and instructions required to flash the firmware.
If you cannot determine the actual tool for your device, post in comments section for assistance.