Epmp 300-25 seeing lots of ethernet failures again

We had this issue early on when 300-25 first came out. using standard POE that comes with the CPE ethernet ports are inop

Running 4.6.1. RC27 tried downgrading firmware, swapping all cables, swapping poe, using short cable on test bench, hard coding to 1gig nothing works port is completly dead. We have a couple that show only 100 meg when connected to Gigabit devices. Swapping SM is the only resolution to the problem. I am amassing another collection so far we have 6 within a week which is very unusual especially since we have force 200 and force 1000 units out there over 3-5 years without issues.

Have you disabled smart speed on your radio? This feature has caused nothing but troubles until disabled

Not an issue with smart speed. This is 100% hardware problem not software.

Sorry, I mis-read your post and thought you had access but were having ethernet issues, serves me right for reading on the go!

This sounds more like either the ethernet transformer or the driver chip being the issue. These are fairly simple to test by swapping the ethernet transformer but unless you are fairly experienced and have a proper rework station you can cause damage to the radios.

Yes the f300 series seems to be more fragile than the 1000s and f200s, but the again we also fix as much as we can in-house and have seen several f200s hit the bench at the same time too.

@accelwireless did you submit a request via support portal?

All of our Force 300’s we’ve pulled out of prod due to this failure.Support can’t help much and will just tell you to change the unit.There is an underlying issue with the ethernet hardware or shielding of the ethernet port. I don’t really understand why they don’t want to come clean on this design flaw or just design a Rev 2 unit.

I’ve seen some guys on the forums have had some success keeping them half stable by putting some sort of inline surge/rf filtering and ups in place between the input power source and poe injector → radio

This won’t be helpful info - but we have hundreds of 300-25’s in the field, and have zero ethernet issues that I’m aware of.

We have seen the same issue where the ethernet port just starts flapping from 1G FD to 100M FD and then eventually stops working.

We have tried cable swaps, connector swaps, power source swaps - it’s a radio issue for sure.

We have experienced the same same issue on a micro scale as we only used the F300 for back hauls. We had what we described as a bad “batch” when we first deployed them with 4 being swapped out in the first 90 days.
We ran fine on the replacement units until about 2 months ago when 3 of the 4 units failed within a 30 day period. We have another link using F300-CSM that has been running solid for awhile now and we replaced the faulty F300-25s with CSM’s.

In comparison, we have a short range back haul using F300-16’s that has been solid for as long as the F300-25s with zero issues.

They all seem to follow the same trend of sporadic ethernet port lock up/drops which gradually worsen until we get tired of the hits or the ethernet port completely fails.

No complaints on the performance but we’ve found their durability to be marginal. As a result we have basically sworn off any F300-25s, RMA’d or not and gone with F300 CSMs.

We thought we were the only ones having “bad luck” Interesting to see others are having the same issue.

The ones that are failing are you guys in hot dry areas. We are are in Southern ca and it’s been very hot. We have seen more failures when the season started to warm up and wonder if there is any correlation? I did open a few up and found what looked like moisture in them but it could also just be some kind of thermal paste but no one has answered me on this from cambium support. Is there a capacitor thats failing and leaking or is this moisture getting in at night when Temps drop quickly and create moisture somehow or is this normal to see this stuff on the chips and heat sinks?

1 Like

We had one lose Ethernet connectivity (port was flapping) right after a freak snow storm. It was fine for 18 months and installed professionally.
Support RMA’d it.

There is a posibility that the large caps could be leaking but you have moisture on both sides of the board so in your case Id say its not a leaking cap.

Its kind of funny about this since here in Saskatchewan we get horrendous rains with high heat (not like SoCal for heat but still plenty hot) and none of the f300-25s I have opened have had moisture in them.

Hi most of ours were also installed in warm/dry weather.

We had really weird ones.We would have ones that would work a couple of months and then start to exhibit the issue and other ones within literally the first week they would start doing this death flap.We suspected cable issues and ran new shielded cables at each of the problematic sites as we though maybe we had water ingress on the cable but problems would keep resurfacing. After replacing with AirFiber or Mikrotik problem would instantly disappear.

We’ve had evidence of moisture in the ethernet jack on 2 units. Possibly a 3rd that we have not pulled from the tower yet. Classic browning/greening in the ethernet port. We haven’t opened them to see the inside but I think I will pull one apart to take a peak. We have had unusual weather this year. We are normally hot and dry but this year we’ve had unusual amounts of rain.


Will give Cambium some slack on this at least.

If your ethernet jack is getting green,browned,blacked then the possible root of your problem is not sitting on their side.

Some brands for whatever reason are more robust than others when it comes to this stuff but eventually you will be fighting ethernet issues down the line if you experience this at your sites.

Agree in theory but only experiencing this on F300-25s. Once is a fluke, twice is a coincidence, three times is a problem. I’ve examined the units myself and can’t see why any moisture would be getting in. Caps are not deformed or cracked. I suspected the installer on the tower wasn’t getting them clipped/seated correctly but can’t prove it. Point is moot for us though as we are no longer deploying them.

1 Like

I agree we see way to many now just like when they first came out. Ours are all at customer homes none were on any towers. 300-16 and 300-13 all seem fine. I would not mind it as much but then we have to stop what we are doing go thru the RMA process, find an invoice from 6 months to a year ago to prove we did purchase them and then submit that to cambium, then go thru the typical test process, to finally get an approvel RMA which we then send to our disty and then thats another process.

The disty approves it and sends us the dish and all which we really dont need we just need the horn. The Disty then says send all the bad stuff back and we have to explain Cambium said chuck it in the electronics recycle bin order to get a credit on our account.

I can’t fathom that Cambium haven’t found the root issue with all the RMA’s everybody has done on the 300-25’s though.

I’ve gone through the same sort of problem with that useless lot at Ubnt and they eventually tracked it down to bad design on one of their products and eventually Rev2’ed the radio.

Might be cheaper for them to just ramp up the internal investigation , do RCA and release an improved/r2 unit than to keep RMA’ing units constantly ? After disassembling 100+ dead ones you should start finding a pattern I take it and work backwards from there ?