Why does the Zyxel Switch cannot boot up properly?

When the Zyxel switch keeps rebooting and can’t boot up properly, they will be unable to log in the switch normally. The cause of this event might be related to firmware or configuration crash. The only way to recover the switch is to reload the switch .bin file and .rom file then use the default login profile and password to log in.

Procedure to upload the .bin and .rom file to the switch: 

1. Connect the switch to a PC via console cable and set the baud rate to 9600. 

2. Power on the switch and press any key to break the boot initiation when you see the log pattern as below: 

3. Type "atba 5" to set the switch console baud rate as 115200 and you need to configure the terminal program baud rate as 115200.

4. Type "atur" and use XMODEM to send the latest .bin file. (File > Transfer > XMODEM > Send)

5. After re-loading the .bin file, the switch will self-reboot. Then repeat step 2 and 3.

6. Type “atlc” and use XMODEM to send the latest .rom file. (File > Transfer > XMODEM > Send)

7. After re-loading the .rom file, please type "atgo" to reboot the switch. Then the switch's console baud rate will change to 9600.

8. Set your terminal program baud rate as 9600, and wait for boot initialization.

9. User can now login with default user-name and password.