MR42 AP suddenly loses power (while direct-attached to PoE port of MX65)

[GR99W]

We've been noticing this behavior on the MR42 APs that suddenly it loses power (directly-attached to PoE port of MX65 appliance) and the only way to recover is to reboot the MX65 appliance. Checked the CAT6 cable - good. Nothing extraordinary is shown on the event log... We're running v14.31 on MX65 and v25.11 on the MR42. Anyone having the same AP or MX behavior? Thanks.

[Adam]

Do you have more than one AP attached to the MX65, if so are they both doing it?  If not can you try switching one of the APs to the other POE port?  Next, I'd try grabbing one of the APs and plugging it in directly to the MX with a short jumper to see if it does the same thing.  That should help start tracking down if it is an AP, MX or cabling issue.  

But I haven't observed that issue in my environment yet.  

[GR99W]

Thanks Adam - In response - no,  only one AP is used.. Every remote location has only one MR42 attached to the MX65 appliance. As I write this, the AP went offline again and I tried using the other PoE port - same result, MR42 AP is still offline (not receiving power from the MX). I'm sure if I reboot the MX appliance, only then the AP will go online again.

[Adam]

I find it super odd that you'd have to reboot the MX because unplugging the AP and moving it to another port should basically do a full cycle of the AP.  When you moved it to another port does the AP get power and no connectivity or nothing? 

[PhilipDAth · Accepted solution]

@Adam when I have seen this happen - I believe the MX65 gets into some kind of funny hardware state.  When it gets into this state it affects both PoE ports. Usually it happens on some semi-regular time cycle (so the problem keeps coming back again and again). The dashboard does not show anything interesting when this happens.

I have seen it happen to maybe 5 different MX65's now. I would call this kind of failure rate low, but its enough that when someone describes the same problem to me again I go "that one again".

[GR99W]

Nope, nothing happens, as if the AP is not detecting the change in PoE port. I have replaced the patch cord, just to be sure. Since the AP is already offline, I rebooted the MX and the AP is now back online.

I agree with @PhilipDAth, I see it in other remote MX appliances too in the field. I already opened a support ticket and hopefully, they will be convinced it is a hw bug or problem. 

Thanks to both of you for your responses.

[PhilipDAth]

I have seen this happen before - and in each case it was a faulty MX65.  It only happens on a small percentage of MX65's - but when you have one of the faulty MX65's it will happen repeatedly.

I would raise a support ticket and ask for a hardware RMA.