Table of Contents
TTL Serial Unbrick
TTL Serial is an advanced unbrick method that requires disassembly and soldering pins, but has the highest success rate.
Serial Parameters
Most router serial parameters:
- Baud rate: 115200 (or 9600, 57600)
- Data bits: 8
- Stop bits: 1
- Parity: None
- Flow control: None
Common Router Pin Definitions
| Brand | TX | RX | GND | Baud Rate |
|---|---|---|---|---|
| TP-Link | Pin 1 | Pin 2 | Pin 3/Pin 6 | 115200 |
| Xiaomi | Pin 1 | Pin 2 | Pin 3 | 115200 |
| ASUS | Pin 4 | Pin 5 | Pin 6 | 115200 |
| Netgear | Pin 1 | Pin 2 | Pin 3 | 115200 |
| Huawei | Pin 1 | Pin 2 | Pin 3 | 115200 |
Serial Tools Recommended
| Operating System | Recommended Tool | Cost |
|---|---|---|
| Windows | SecureCRT / PuTTY | Free/Paid |
| macOS | CoolTerm / Serial | Free |
| Linux | minicom / screen | Free |
Operation Steps
Connection Phase
- Locate TTL pins on router motherboard (usually near Ethernet ports)
- Use USB-to-TTL module to connect to computer
- Open serial terminal software
- Set correct baud rate
- Connect RX, TX, GND (note: RX connects to TX, TX connects to RX)
Unbrick Phase
- Open serial terminal
- Power off the router
- While monitoring output in terminal, power on the router
- Observe boot log, press any key to enter U-Boot
- Set TFTP parameters in U-Boot command line
- Use tftpboot command to load firmware
- Use erase and cp commands to write firmware
Common U-Boot Commands
setenv ipaddr 192.168.1.1 setenv serverip 192.168.1.100 tftpboot 0x81000000 firmware.bin erase 0x9f000000 +0x300000 cp.b 0x81000000 0x9f000000 0x300000 reset
Notes
- TTL voltage is 3.3V, do not connect to 5V
- Router must be powered off when connecting
- Some routers need Flash chip removed before safe flashing
- Serial connection cables should not be too long