Appendix 3. Firmware Recovery - ZyXEL Communications ZyWALL USG 100 Release Note

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Appendix 3. Firmware Recovery

In some rare situation, ZyWALL might not boot up successfully after firmware upgrade. The
following procedures are the steps to recover firmware to normal condition. Please connect
console cable to ZyWALL.
1. Restore the Recovery Image
If one of the following cases occur, you need to restore the "recovery image"
Booting failed, device show error code while uncompressing "Recovery Image".
Device reboot infinitely.
Nothing displays after "Press any key to enter debug mode within 3 seconds." for
more than1 minute.
Startup message displays "Invalid Recovery Image".
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