Flash International Firmware on ZTE E1600/E2603/E2615

I. Prepare

• A USB-to-TTL adapter using an IC such as CH340, CH340G, or FT232. I use this FT232 .
• If you need a device for practice, see the ZTE E1600/E2603/E2615 on Shopee .
• A LAN connection to the PC.
• Three copper probes for the board (1mm copper wire sharpened at one end).

Make sure the probes are secure. Do not touch or move them during the procedure because an open or short connection can damage the board. Soldering the wires is safer when possible.

• Download and extract this archive . It contains mtd1, mtd2, mtd3, mtd4, mtd5, and upgrade.bin.
• Temporarily disable the PC firewall so the TFTP server can work.

II. Connect UART

• Disconnect router power.
• Install MobaXterm on the PC.
• Connect UART to the motherboard as shown.

!!! Do not connect VCC. !!! Be extremely careful not to short GND-VCC or VCC-RX-TX. !!! A careless connection can send voltage directly into the CPU and kill it.

 UART wiring diagram

If no log appears, try swapping RX and TX.

After securely connecting the board:

1. Connect the USB adapter to the PC and identify its COM port under Device Manager > Ports (COM & LPT).
2. In MobaXterm, open Session > Serial, select the COM port, set Speed (bps) to 115200, and click OK.
3. Power on the router. If UART is connected correctly, many log lines appear. Press 1 repeatedly to enter the console until the login screen appears.

Enter password 5cE080@fyBD exactly, including uppercase and special characters, then press Enter.

III. Flash firmware

• In Windows IPv4 settings, set:

  • IP address: 192.168.1.100
  • Subnet mask: 255.255.255.0
  • Default gateway: Leave empty.
     Screenshot

    

• In MobaXterm, open Server > Server management, open the TFTP server settings, and set its root directory to the folder containing mtd1–mtd5 and upgrade.bin.

• Click Play to start the TFTP server. The free version limits runtime; click Play again when it expires.

When TFTP works, the console shows Loading and many # characters.

Only after the transfer succeeds, run:

Restart and update firmware through TFTP:

1

reset

Immediately press 1 repeatedly to enter the console and enter Boot4128s! when prompted. Keep the TFTP server running, then enter:

Factory reset and web upgrade

1. After the mesh unit boots, press the upper rear hardware reset button. If the modem does not show a red LED after reset, unplug and reconnect power.
2. Set the PC LAN interface back to DHCP and open 192.168.1.1 with admin/Haikui_V2.
3. Upgrade again through the web interface using upgrade.bin from the extracted directory.
4. Perform another factory reset after the mesh unit boots.

This guide references the work by @MinhChungIT on VOZ.VN ( original thread ).

Good luck.