The DLink DIR-819 and ZyXEL EMG1702-T10A share the same hardware specs and the same bootloader. The images are identical, except for some partition atributes.
TBS routers use a 90 bytes header for upload in the web interface. This header is only used for the factory install.
Sources:
Specifications:
SoC: MediaTek MT7620a @ 580MHz
RAM: 64M
FLASH: 8MB
WiFi: 2.4Ghz SoC-integrated: MediaTek MT7620a bgn
WiFi: 5GHz radio MediaTek MT7610
UART header on PCB (115200 8n1)
Installation:
- Rename the factory image to factory.img
- Upload the image using the web interface
Revert to the vendor firmware:
- Remove the header (first 90 bytes) from the
vendor firmware and do a sysupgrade.