I recently bought RB4011IGS+5HacQ2HnD-IN which comes with POE out on ether10, but when I connect my modem to this port I got no link and modem does not get any power which is working fine with external POE adapter and with pressing Cable test it will show the cable is shorted 28m (cable length is about 29 meter), How could it be shorted when it’s working fine with adapter!?!?!?
I tried forced on and no difference whatsoever. and I really want to use the POE out of the router not an external adapter.
Cable is a CAT6/SFTP 95% about 29 meter long
Image: are shorted blu and brown pairs.
What device is the “modem”?
So I got to change the cable? or sockets?
Can be a 568a or 568b wiring problem?
What do you suggest?
ZLT P19H
I do not find much information about ZLT P19H
But is 15V device, probably do not work with 24V poe as 4011 have.
About ZLT P19H it's very similar to YF-P11 and about this it said Power Range 5V---18V
In this page: https://yifanwireless.com/outdoor-4g-cpe/yeacomm-yf-p11-ip66-4g-lte-outdoor-cpe-with-lan-port-.html
about 4011 mikrotik said "PoE out Passive PoE up to 57V " not sure what is minimum voltage but I didn't found anywhere anything about 24V
and if by 24V you meant the base DC jack input voltage and cause it's 24V the router doesn't decrease it, so I can give the router 12V or even 15V or 18V cause it's "DC jack input Voltage 12-57 V "
right? it should fix it?
If you not have already broken the modem forcing PoE with 24V from RB4011,
you can try to power the RB4011 with 15V and using a sufficent Watts power source for power both 4011 and modem.
If the modem use 500mA @15V, if you decrase the voltage the mA needed are more, and the 4011 can’t release more than 500mA from PoE out
No it's still working 
Okay I will try this see how will turn
The poe-out port can power other passive PoE capable devices with the same voltage as applied to the RB4011iGS+5HacQ2HnD.
Make sure you choose proper PSU.
I try to use a 15V input voltage for 4011 and it worked.
Thanks a lot man
Yeah I change the input voltage and the POE out start working.
Thanks for your reply