XD4-240 overheating?

XD4-240 overheats and locks up if the environment temperature reaches 80F.
It looks like main processing board locks up, but not the IAPs, so all the wireless clients remain connected to IAPs, with no network access.

The fan is working.
Is that normal or I’m missing something?

This AP does not have an active care plan

1 Like

are you saying that the ambient air temperature is 80F (so barely over normal indoor room temperature) and the unit is not functioning properly? This AP does not have an internal fan. Does the unit function properly when the air temperature is below 80F?

Unit functions perfectly if the ambient temp is less than 80F.
It was woking fine for 3+ months, and it’s only few days when temperature started to raise during the sunny days (Florida). Once room temp gets over 80F (never over 81F), it locks up in an hour or two.

Also it does have the internal fan for sure.
SKU: XD4-240

My guess is that I would have to remove labels, unscrew the mainboard and see if any thermal compound needs refreshing. The upper plastic part is removable with 4 unsealed screws and there is a fan in the center of the unit.

1 Like

If I would re-plug it immediatly, whle it is still hot, it would be stuck in the bootloader forever.
(status led green, all IAP leds orange+green)

Opened it.
I think it is a manufacturing defect for this exact unit.
There is no thermal pad between the CPU and metal heatsink, that is mounted on the plastic case.
Given there is a pocket on the heatsink part - CPU is not even touching it.

my error yes it has a fan. This seems to be a build error. I assume you have other units and they run fine at higher temperatures correct? This looks like it needs to be sent back to us via RMA

Yes, 3 other units run fine.
I would just add a thermal pad, between the CPU and heatsink, as it is open anyway.

If I were Cambium engineer I would probably want to implement a hardware watchdog (in future models), that would remove power from IAPs, if main CPU has failed. Otherwise wireless clients are stuck connected without network.

Didn’t help much.
78F right now, AP locked up.

Turn the AP off and let it cool down. Then power it back up and start executing the CLI command “show temperature” every minute or so until it stops working. Post your results. Thanks.

Thanks for the advice.
I wrote an automation script to do this and let’s wait when it locks up, I guess it would happen only tomorrow.

I would publish results here.

Does not make any sense.
It locked up when last “show temperature” was

Array Temperature          C    F
-----------------         ---  ---
Controller                 45  113
Fan Speed                1632  RPM

Where the thermal sensor is located?
Somewhere on the board, but it is not the CPU core temperature?

Was working fine whole weekend with room temperatures beeing below 76F, today it is slightly warmer and it did lock up. So it is for sure overheating.