Help - SXT SA5, voltage on data lines

Hardware MikroTik hardware general
1

Hi all!
I have a strange problem, which i haven’t discovered until recently.

One of our SXT SA5 units, when connected to a PoE “returns” voltage to data lines. Orange/whiteorange are +12v (of course if I use 12v DC PoE) and greens are ground/zero. There is no corrosion and no visible components damaged and it’s Working great! It was working like that for, probably, 2 years, connected to another Mikrotik (some RB) … I have discovered the returning current when I wanted to remove that RB and I fried one router and one switch :wink:

I still could use this SXT but the device it is connected to would have to deal with this current - I’ve tested one rb450 and it’s getting HOT … but working …

Any ideas what part of SXT is broken and how to fix? Any idea what to put between two devices to cut this DC from green pair?

Cheers,
Dejan

2

Do. you Use the Gigabit poe Adapter that Gomes with the sa5 or did you Use the something Else?

3

Hi,
Whatever I do/ whichever PoE I use, things are as they are … + on orange pair … if I put 12V - I get 12V; 24 - there’s 24 :frowning:

Dejan