WARNING: SXT PoE Injectors

Hardware MikroTik hardware general
1

We just had to replace a bunch of SXT injectors (beige/gray pigtail) since we had flapping and/or links at 10M on a campus style install with SXT Lite5 devices.

After much swapping and experimentation we discovered replacing the beige/gray injector with either the white gigabit Mikrotik injector or other non-Mikrotik injectors resulted in a solid 100M link.

We stripped the jackets on the MT injectors and found the injectors do not use twisted pair from the plug to the jack. So there is 6" or more of untwisted wiring from jack to plug…my jaw is still on the floor.
Again, this is the beige/gray pigtail, not the white gigabit injector. You can look at the plug and see black, red, green, white for wire colors.

While installers are diligently trying to keep pair untwist to a minimum, this injector negates those efforts by far.

This is a poor way to save cost and clearly out of spec with regard to TIA-568 untwist length of 13mm / 1/2".

We have also noticed that some of the injectors have a metal shell on the plug that is attached to a drain wire, but the wiring is the same. So if you are expecting a foil jacket, and stp with drain end to end, it’s not there.

I have pictures.

2

It would be better if Mikrotik sold products without PoE Injectors.
Anyone can buy different injector - Better quality of injector or poe switch…
Quality of POE Injectors (original MT) is very bad… :cry:

3

I had a similar problem with a SXT Lite 5 and a CRS-125.

You can see my post here http://forum.mikrotik.com/t/port-flapping-on-crs125/82465/1

I ended up replacing the passive POE Injector with a third party one as well.

chris.

4

Mikrotik should be embarrassed to ship this thing. I’m still shocked. Who would think this is acceptable?

On the jack end, the 4 wires make 2 really tight 90’s and then are soldered onto what looks like a connector intended for PCB’s.

I’m going to tear down a gigabit and compare…

5

Good news on gigabit. The one I skinned has a foil shield, drain wire and twisted pairs.

6

This is big problem! No twisted pairs.
A lot of Ethernet problems is caused with original “NON TWISTED” poe injectors.
From now all originals poe injectors flying into the trash!!

7

Same problem here.

We’re suffering strange issues with some customers: random packet loss, ethernet interface going down and up few times every day…

We checked some installations with Fluke, and they passed certification.

Checking all them… all have SXT Poe. Those that have UUU PoE, or router with integrated poe has no issue.

Replacing it with gigabit one from Mikrotik and weeks without any issue.

Now, we have to replace about 200 PoE.

Everybody will like a replacement program… but anybody expects it from Mikrotik. But at least stop sending this garbage!

8

+1

9

+100

10

Similar issues here but with some white poe injectors from basebox2.

11

Same issues, random packet loss, ethernet interface going down and up few times per day. Every PoE injector from SXT going to garbage directly from box :frowning:

12

I also have problem with mikrotik poe injectors. Many of this is corrupted “out of the box”.

13

100Mbt or Gigabit?

In both cases, soon we will have new and improved injectors. Transition takes a while, since the devices are already pre-packaged with these, but in future, we will have better injectors.

14

Mine are white, suposed gigabit for basebox 2.

15

We have problem only with 100Mbit injector. At this moment we do not use them at all.
Can you share with us new improved injector? Will be twisted pairs?

16

I wrote about 100Mbps.
With gigabit injector i have different problem. They are loose in some RB ethernet ports (eg. 260GS) and causing disconnecting. But this issue was with first gigabit injector. Newer seems better fit to the all RB ethernet ports.