Thank you for your quick reply.
OK, I found the thread you mention:
http://forum.mikrotik.com/t/v7-16-2-stable-is-released/178911/1
Unfortunately, I don’t understand from it what exactly I should do. Does it suggest that 7.16 is buggy? If yes, is downgrade to a good version possible?
Your ATL is probably configured with DHCP client and not with a static IP address? 192.168.188.1?
I have not touched it for a year (since purchased), so I don’t have it all in my head. The IP address of the ATL is 192.168.188.1. I believe the rest is pretty much factory default.
I am not quite sure what is the difference between:
A) PoE power coming from the injector and Ethernet connected directly to the computer (not through hAP3)
B) PoE power coming from the injector and Ethernet connected to hAP3
Anyway, I followed your advice and disabled the PoE out on the hAP3 port and connected the power injector in between hAP3 and ATL.
[admin@MikroTik] > /interface/ethernet/poe/print detail
0 name="ether5" poe-out=off poe-priority=10 power-cycle-ping-enabled=no power-cycle-interval=none
Sadly, the result is still the same as in the OP - can’t connect to the ATL. I also still see the LED of the ether5 port going dark for about 3 sec from time to time (not sure if this is normal, haven’t paid attention before the updates).
your ATL maybe faced power interruption while updating.
All my equipment is UPS powered. There have been no surges or power outages during the update either.
So, what can I do?