Hi,
I have ePMP 450 High gain SM (Model # : 5094hh) and cannot access using 169.254.1.1 IP and need to reset back to factory default. There is no Reset button or RJ11 interface. I can see only PoE port and a audio like slot.
1 Apply power to PSU for at least 10 seconds.
2 Remove power from the PSU, and then re-apply it as soon as the power indicator light goes out
(about 1 - 2 seconds).
3 When the unit is in recovery mode, access the web interface by entering the default IP address
169.254.1.1. The Recovery Image Warning page is displayed.
4 Review the Boot Selection (Recovery Options attributes).
5 Select a recovery option
Have you opened a support ticket? They should be able to assist you with troubleshooting.
Submit a ticket on the support portal. https://support.cambiumnetworks.com/
If you never get a ping response on 169.254.1.1 even after a short power cycle, that is not good and the unit if still under warranty might need to be returned.
As mentioned, the support ticket will be able to answer that for you.