WS-12-250-DC - only fan and power led on.

[lsettembri]

Hello and thank you for reading.
This is the 3rd. time I come accross the same problem, with 3 different units. I hope someone could give us some feedback in order to prevent this from happening in the future.
The situation is as follows:
The WS-12-250-DC shutsdown all devices connected to it. When we arrive to the towers, we find the unit with just the fan and the power led on, thats all. Everything else, dead. The unit does not respond to anything, not even reset.
After replacing the unit, we then find that one of the UBNT devices does not respond either, seems like the Netonix somehow have sent more voltaje than 24v. to one of the ethernet ports, troubling the radio. This has happened, the three times, in different ports, but always in one.
In both towers that this has happened, it seems the issue came from the battery charger or the solar regulator. In both cases the charger/regulator were connected to the batteries, and the Netonix connected directly to the batteries.
We end up chaging three devices everytime: charger, netonix and radio.
The netonix are grounded.
The main concerns are:
1) why does the Netonix behaves this way?
2) believing that the original issue came from the charger, is there any way we could avoid the netonix troubling whatever is connected to it?
I hope I have made my point accross, sorry my English is pretty basic.
Thanks again,
Luciano

[sirhc]

You are making an assumption that the Netonix is doing something wrong.

You are "guessing" that the Netonix switch applied 48V to a 24V configured POE port.

I can tell you this is not possible, a port that is configured to 24V will not put out 48V.

A port that is damaged from shorted cable can damage the MOSFET circuit so that what ever POE was configured on that port will always be ON as explained in this post: viewtopic.php?f=17&t=2559&p=17930&hilit=MOSFET#p17930

You say the Netonix is grounded and I assume the tower is grounded but are the electrical service ground rods and the tower ground rods bonded together with a heavy wire?

So you have a dedicated ground wire up your tower and tied to each radio and or radio mount to provide a dedicated ground path for ESD and Static charges so they do not follow your Ethernet cable to ground?

If not then if you have ground potential shift this current runs across the ethernet port cable and can fry the radio and/or the switch.

But then again I am guessing as I would need to examine the switch to find out what happened to it.

Here are some posts on proper grounding (REALLY READ THE WHOLE POSTS):
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=30&t=1429
viewtopic.php?f=17&t=1786&start=30#p13447
https://community.ubnt.com/t5/airFiber/ ... rue#M31070

There are some MODs you can do to our switches to make them deal with ground current potential difference better as explained in this post.
viewtopic.php?f=17&t=2493&p=17453&hilit=MOD#p17448

All switches being manufactured since September 2016 have this MODIFICATION to better help them survive people not doing proper grounding.

[lsettembri]

Hello sirhc, thank you very much for the prompt reply.

I will definitely read the posts you have provided, however, can I please make a quick question.

The netonix is not able to pass more voltage than planned, what could then be the reason why a radio connected to switch will become un-responsive? In one of the three occasions I have mentioned, while we were at the tower, we had a problem with a charger, that troubled the Netonix and one radio connected to the switch. This is the 3rd. time something like this happens. In the previous times we had thought this was related to storms, that would trouble a radio and therefore the switch, but then we are finding ourselves with sunny days, and netonix swtiches and radios becoming dead.

Furthermore, what could be the reason why the Netonix only has the fan and power led on? I've done some research on the forum, but could not find an answer.

I would love to send the units back for investigation, but I live in Argentina and this is probably not a possibility.

On the first occasion I had thought this was related to grounding, but since this has happened 3 times within a year, only with Netonix switches, in 3 different towers, when nothing like this has happened in the past (with different switches), I thought I should ask. I will read the posts!

Thanks again!
Luciano

[sirhc]

The power LED on and FAN running will be caused by one of following:

1) Firmware on switch is corrupted:
Have you tried hooking up a console cable and seeing if the switch is failing to post all the way possibly from corrupted flash?

2) Board is damaged from ground current:
If the board is fried from ground current the fan will always be on HIGH and the power LED on.

If your not going to RMA the units then why not open them up and remove the switch boards and take hi resolution pictures with your phone of the top and bottom of switch boards and post them in this thread. If it is ground current damage most times I can see damage to ESD protection DIODES, Current Sensors, or MOSFETs.

If the boards are damaged then you can purchase replacement boards from us.

If I do not see visible damage you could try postal mailing just the boards back to me and let me look at them.

[sirhc]

Once again I outlined what we are now doing to make the switches more durable to ground current from poor grounding in this post.

viewtopic.php?f=17&t=2493&p=17453&hilit=MOD#p17448


If you are good at soldering you could to the MODs yourself.

[lsettembri]

Hello sirhc, thank you very much for the reply.

I attach pictures of the board. Please let me know if you need a better picture.

I wonder, this switch is power supplied by batteries, which are charged by a solar regultor, which I think may be the origin of the problem. Is there any way I could protect the switch from this? The netonix then blew a PB400, is there any way I could protect whatever is connected to the switch?

Thanks again!
Luciano

[sirhc]

1) Did you hook up a console cable like I asked and see if the switch is outputting anything?

2) You're going to have to REMOVE the switch board from the chassis and take good CLEAR pictures with plenty of light so I can zoom in and see details. You need to take picture of top and bottom of board. Take note to where each cable goes so you can put back together. Maybe take pictures of all cables before you take apart.

As I said my guess is the switch was damaged from ground current. Did you read the grounding posts I linked you above?

Here are some posts on proper grounding (REALLY READ THE WHOLE POSTS):
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=30&t=1429
viewtopic.php?f=17&t=1786&start=30#p13447
https://community.ubnt.com/t5/airFiber/ ... rue#M31070

People incorrectly think ground is ground and this is not the case. A ground potential difference is a LOT of current and can fry equipment. YOU MUST BOND TOWER GROUND RODS WITH ELECTRICAL SERVICE GROUND RODS - READ ABOVE POST LINKS ABOVE.

I also linked above some modification you can do to make your switches better deal with ground current from poor grounding.

There are some MODs you can do to our switches to make them deal with ground current potential difference better as explained in this post.
viewtopic.php?f=17&t=2493&p=17453&hilit=MOD#p17448

If you are skilled at soldering I would suggest you make the modifications explained in the above post.

All switches being manufactured since September 2016 have this MODIFICATION to better help them survive people not doing proper grounding.

But most importantly make sure your tower ground rods are bonded to your electrical service ground rods to prevent ground current damage. READ THE GROUNDING POSTS ABOVE.

My guess is ground current took out the switch and the one radio that was the path that the ground current took.

You can RMA just the switchboard or boards and send in a small box via Postal Mail. If the boards are damaged we will fix if possible for a small fee or replace them at cost and ship them back via postal mail in a small box.

Your pictures are a little dark and I can not see clearly but is this component damaged?

If this is damaged and you have no serial console port output then most likely your board is damaged beyond reasonable repair but we can sell you a replacement board.

As I said make sure your read grounding posts above and properly bind tower ground rods to service ground rods:
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=30&t=1429
viewtopic.php?f=17&t=1786&start=30#p13447
https://community.ubnt.com/t5/airFiber/ ... rue#M31070 [/quote]

Also you might want to modify all your switches with the MODs explained in this post:
viewtopic.php?f=17&t=2493&p=17453&hilit=MOD#p17448

[Groong]

Same thing happened to me today. Went up to site, only power light and fan at full speed. Replaced it with the same model. I went back to the bench with it, tried reset, and hard reset, no go. It only had one input from router and 4 poe 24V sectors on it. I have two other 12-250's working, and two AC's working. First time this has happened, but if it happens again, and we don't know why, we are going back to toughswitches. Any thoughts?

Best,
Phil
Can I remove warranty sticker to look at board? It's less than a month old.

[sirhc]

Same thing happened to me today. Went up to site, only power light and fan at full speed. Replaced it with the same model. I went back to the bench with it, tried reset, and hard reset, no go. It only had one input from router and 4 poe 24V sectors on it. I have two other 12-250's working, and two AC's working. First time this has happened, but if it happens again, and we don't know why, we are going back to toughswitches. Any thoughts?

Best,
Phil
Can I remove warranty sticker to look at board? It's less than a month old.

I do not see how it is less than a month old since we stopped putting those decals on almost a year ago.

Go ahead but if it is ground current or shorted cable damage you may not see the damage without removing components fist.
I would RMA the unit as we provide detail report with pictures of what we find.
If it was a failure we repair and return for free but if we find damage there is a repair fee.

Our damage reports most often include pictures especially if the unit is within warranty period.

On older units way out of warranty we do not always include pictures to save time as it is out of warranty anyway but we explain what we found and how to correct it from happening again.

If your unit did suffer ground current shift damage it will occur again unless you fix it. Ground current shifts occur from rain, insufficient grounding rod potential, or from neighboring sites as all services in the immediate area are all bonded together via the electrical company as ground is bonded to neutral in all panels and they hand you HOT, NEUTRAL, AND GROUND

Below are some examples of RMA repairs:

As far as grounding all we do is preach grounding and some people listen others do not.

99% of all WISP equipment damage is from ground current (I own a WISP)

Here are some good posts on grounding:
viewtopic.php?f=30&t=2786#p19279
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=17&t=1786&start=30#p13447
viewtopic.php?f=30&t=1429

Read the posts above but the basics are as follow:

Tower ground rods must be bonded to electrical service ground rods HEAVY #2 wire.
I always add 1 or 2 “new” ground rods to older existing electrical services.

[Groong]

We will RMA the unit. It was purchased via Amazon. Possibly the seller had it in stock for that long? I'm just the installer, I'll bring the unit back to the boss who purchased it and he'll return the unit this week most likely.

Thanks.
P.
Here are pics of new unit, just arrived yesterday:

Has warranty sticker on it