If your NBN modem is exhibiting no lights and a clicking sound after a thunderstorm, it could indicate damage from a power surge. Attempt to unplug and wait for 10 minutes before reconnecting. Check different power outlets and inspect the modem for physical damage. If these steps don't resolve the issue, contact your Internet Service Provider for assistance or consider seeking help from a professional technician. Thunderstorms can cause electrical damage, so exercising caution is essential. ... View more