PMP450i Extreme Cold Weather Issues?

Hey folks,

Anyone have experience with PMP450i Access Points failing in cold weather?   

A bit of context... this past weekend, we had a significant cold snap, with temps dipping to around -40 Celsius with the windchill.  I had two PMP450i 900Mhz AP's, on different towers, fail within 18 hours. And when I say fail, I mean they just died.  They will not power up at all, no lights, no ethernet connection.

It's hard to say if their untimely demise was a result of the cold, but it was rather coincidental.  On what was this region's coldest three day period of this winter season so far, two 14 month old AP's die so close to one another.  However, these are not uncommon temperatures for this area, and I believe they would have been subjected to similar temps last winter.

So anyways, they were purchased in the same order, so perhaps we got a couple in our batch that had manufacturing issues?  Or maybe it was indeed the cold...I don't know really know, but I believe we are going to attempt to RMA them.

Has anyone else had a similar experience with a 450i AP conking out in the cold?

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We have had the same experience 4 900 MHz 450i APs on 4 differnt towers just died in the cold, the other APs (900 450i) on the same tower have been fine. Same cold weather, I am located in Bracebridge Ontario 

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If the units are under warranty, we will certainly honor this failure reason. This is not common, as we certainly test all designs against the full operating temperature range in the specfication.  I have not heard of any systemic issues affecting large numbers of 450i units.

- 25F  here today and it looks like we might have lost one of our 450i AP's as well. 

-21C here now and we have had no issues since we lost the 4 APs last week

Neil, JW1 - Have you guys opened support tickets? If you want to send me the ticket numbers, I think our engineering team would be very interested in getting the failed units back to analyze the failure mechanism...

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We definitely will when we are able to retrieve the AP, it will probably be next week at the earliest for us to get it down. 

Thanks Matt, we haven't opened a ticket. We were going to return them to a 3rd party repair service as they are out of warranty

As of today we are up to 8 PMP450i 900MHz Access Points offline.  There is clearly a design flaw in these devices related to cold weather.  No other PMP450 has been affected.

Has everyone confirmed the unit is dead or does it return to normal operations once warmed up?

Ours did not power up after there were warmed.

I haven't checked but I believe all the APs we had that were effected were bought at the same time in early 2017

I confirmed that our radios didn't power up when warmed-up either, very unfortunate. 

No other 450 or 450i AP's affected, and we bought these radios in a large batch in early 2017 as well(same time as Neil Smellie, perhaps a bad batch?), so we are kind've on pins and needles till the weather warms up, desperately hoping none of our other 25+ 900Mhz 450i AP's die.

I will be entering support tickets today, and will forward the info to you Matt.

Edit: Found out we bought these radios in November 2017, not "early 2017" like I described earlier.

Regarding weather.

Was it a "bad Batch"?

Appreciate the sharing of knoledge.


We are in process of obtaining some of these from affected customers... will update this thread when more is learned.

Yes, I had a 450i 900MHz lock up in the cold as well last week.  Warmed up, and on the desk, still no power.  I swapped in a spare and the spare is working fine.  

Purchased in 2017.  We haven't had a cold like this since it was deployed.  I'd say it was -15 or -20 when it died.

Matt, do you want ours back too?

Yes, please... please open a ticket.  Support is well aware of this issue, and we need to dig into the failures to determine what's going on.

I opened a ticket but Customer support is telling me the AP warranty expired Sept 2018 and it's not covered under the new 3yr warranty.  I was quoted $500 to repair.

FVI-  I am checking into that right now.    We should be able to take care of your radios.  


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Thank you for handling this Dave!

Correction to Dave's post: we WILL take care of this radio.  It is correct that radios purchased before 2/1/2019 are not automatically covered under the new warranty terms, but in this case, we have an issue that will be resolved.

We are still working to determine what's going on here. Stay tuned.

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Dave, I was quoted the same for one of the two of my radios, the other is still under warranty.  I guess this must be based on manufacture date instead of purchase date, because we ordered all these at the same time.

Thanks to Cambium for stepping up and taking care of this for us.