difference between POE or Jack?

Hardware MikroTik hardware general
1

I have this rb433AH which according spec (http://routerboard.com/RB433AH) accepts 10…28V on both Jack as well as POE.

I have one 12V adapter. If I plug it in the jack the boards boots up and starts normally.
If I use a power shot (supplied with the Grooves) to feed same 12V into a 1mtr patch cable the board is not booting. It flashes when insert the jack into the jack of the powershot. Actually when I just touch the adapter jack against the male jack of the powershot the board boots and runs. When I slide male into the female like it should no more power goes to the board.
This only happens with 12V adapter. If I use a 18V or higher I have no issue.

It cannot be the adapter (1.5Amp) because boards boots normally when jack goes straight into board.
It cannot be the power shot because with 18V adapter board boots also normally.

Anybody that has a clue?

2

There are and will be Voltage drop on Ethernet cable - it looks like your PoE voltage dropped below acceptable level.

3

when you power by PoE you can use voltmeter to measure what voltage you have on Jack

4

I don’t think this is the issue here. First the cable is only 75cms long and secondly, if I just put the jack male of the adapter and female of the MT split cable to eachother (so not sliding in!) the boards works perfect. Only sliding the male a mm into the female part makes the board to drop.
On 18V not the same issue.

But I am waiting for my voltmeter to come back and will test the voltages on the jack while supplied by the board to the poe.

5

What do you want to say about male and female parts?? :open_mouth: :laughing:

6

Not sure this is related, but I have seen some problems using some power supplies with some MT products.

In particular, I have a box full of 12V supplies from Leader Electronics. 12V 1A.
I use these for flashing and config. A bunch of them on a power strip waiting for a device.

I have never had a problem using these until I tried using them with 750GL’s.

On my desk right now, I have an RB250GS, an RB450 and 10 RB750GL’s. There is a dramatic difference in the distance from the front face of the DC jack to the positive pin on the RB750GL’s. The 750GL pins are set back about twice the distance as the 450 and 250. That is causing all sorts of trouble with my legacy supplies. If I wiggle the cable, the 750 reboots.

This appears to be a defect as I have never seen the center pin set back so far.

7

there is a little voltage drop na poe port, like 0,5 to 0,6V + power loss on cables…
I recommend at least 18V power suply. We are using cheap notebook adaptors with 19.6V, for a long ethernet cables (50m+) 24V is only option. (19V power source 9V on RB, 24V power source 22V on RB)

8

Did you report to your supplier/Mikrotik? This seems a production error that should be corrected.