Hey folks!
Ive been trying to find any topics with this issue, but I coudnt find any.
We’ve got quiet a few powerboxs out there and they all got the same issue, I upgraded some of them to the lastest version of OS and the issue still there.
If anyone know about this please let me know 
Cheers!
Nobody knows anything? 
Hello,
What is other end of ether4 and do you charge it by Poe-Out? Have you check different ethernet cables, to avoid situation they are faulty?
So few powerboxes and all have same issue, flapping ethernet4?
Cables been tested and they are ok, we tried in that pb another port before. All the power boxes got the same issue, ports going up and down like a yoyo, we got more than 30. Today I just realised when I was trying to access an AP connected to The power box, the port just flapped and rebooted the access point when I was trying to login…
Is not always on port 4 some of them in port1 even. Is a really odd behaviour.
Thanks for your message!
You still haven’t answered my question about what is other device. For me this seems more like hardware issue. If you don’t use poe-out, try to:
/interface ethernet set ether4 poe-out=off
If you use poe-out, then you should calculate do RB 750P r2 have enough resources(input/output/other unit consumption) to power other device/es.
We do use the POE out, we have access points connected to it.
All the pbs got the same port flapping issue, all of them, i can take screenshots.
And the interfaces going up and downs are rebooting the access points cause I can see the uptime.
Have you tested all 30 Powerboxes with same Poe-out boards(access-points)? How long is poe-out cable? And do boards touch outside environment?
I just don’t want to believe it’s hardware issue for all 30 PB. 
What kind of cable? Shielded or unshielded? Have you tried different cables?
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I know of someone having an issue with PowerBox and the Ubiquiti Rocket M5. See another thread.
It may be that some devices cause issues. It has not yet been fully investigated.
Please tell us the length of the cable…if you are using a cable that’s more than 20 meters you could have this kind of problem.
I experienced the same with my RB750Pr2 and Omnitiks with PoE-Out.
After 20-25 meters there isn’t enough power to power up the device on the other end.
Try to connect on ether-4 another device with a shorter cable to confirm this theory.
In case you are on a tower and are unable to use a shorter cable for the devices in production just try to downgrade to the 5.25 RouterOS version (if the PowerBox is quite old should be able to go back to that version). In older ROS versions there was a flag to check in case you used a long cable: if i remember exactly it was under the Ethernet - PoE menu.
We had The Same issue with unshielded cables, use shielded and Problem is gone!
We tried different cables and still same problem.
We use really short cables, so thats not the case.
We use Ubiquiti Tough cable for all these setup.
Have you ruled out moisture building up inside a cable and working its way inside the PowerBox?
You mentioned that you were using Ubiquiti FTP Cable. Are you also using the metal jacketed Tough Connectors and ensuring that both the ESD drain wire and foil make contact with the metal jacket?
Do you use any Ethernet surge protectors? If you’re using the Ubiquiti Eth-SP then throw them out as they are complete garbage.
What do you do for earth grounding and how do you deal with static building up on the access points?
As someone else previously mentioned, have you done the math on total power being consumed (max 2A combined)? Have you also checked for potential voltage drop in the PoE supply going into the PowerBox?
I have several of these deployed without issue; up and running for months and months on end.
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Hey
did you find any solution ?
i am facing same problem with 3 power box pro
each power box pro powering 1 ubnt & 2-3 basebox with sectors
base box restart randomly
Same here, we have replaced old powerboxes in some sites for new ones with cat6 patch leads and we still having the same issue.
There is not confirmed hardware problems related with the PoE-Out on these devices. PoE out status is dependent on multiple factors, for example, the voltage drop on the wires which powers your PowerBox, and the voltage drop in the wires that goes to the powered devices, both will cause current flow to increase. If the total or port current limit is reached, the PoE will be turned off.
At first, I would suggest you to update your RouterOS to the latest RC version, where PoE logs are added, you will see the reason why the PoE is disabled.
In case if you are powering multiple devices, change the problematic port priority to highest:
https://wiki.mikrotik.com/wiki/Manual:PoE-Out#setting_up_priority
If the problem remains, plug problematic device to some other port
If the behavior is the same, generate a supout file, and send to support@mikrotik.com, with a description of your setup.
https://wiki.mikrotik.com/wiki/Manual:Support_Output_File
We upgraded to the 6.40.3 so we will see how it goes now. We have tried the POE Priority before and didnt do anything.
If issue still going after this upgrade we will send that file to support.
Thank you.
Cheers!
We just replaced our 48v- 24v converter with branded 2 amp mean-well supply & all problems gone now all power box working fine.
check your power source again.