5 GHz Wi-Fi card sometimes not detected after reboot (ticket #002646)

Hello, I’m starting this topic because the tech support can’t help me for a year.
Please see ticket #002646.

I have Turris Omnia from Indiegogo, 1 GB RAM, Serial starts with “4”.

After router reboot, with about 30% chance 5 GHz Wi-Fi module does not get initialized and 5 GHz network does not work unless the router is rebooted or power-cycled once more.
The module is not seen in dmesg or lspci/lsusb.
The issue was present from the very beginning of using the router, but I blamed early software and hoped it will be fixed later.

I’ve tried:

  • Resetting the router to factory settings
  • Re-flashing from emergency mode to stock firmware with full reset
  • Swapping card ports (took off 2.4 GHz card off and put 5 GHz one in its slot)
  • Sending the router to Turris, for warranty repair (24.10.2018)

Turris did not diagnose any issues with the router.
Unfortunately, the problem persists. I had to disable automatic updates because I got broken Wi-Fi connectivity once in a while, and I not always could physically power-cycle the router to fix it.

The router is placed in a well cooled clean room. The software is almost stock (it was full stock when I experimented with 5 GHz card only, to exclude software problems). I’ve disassembled the router and checked all connections, re-plugged the cards to make sure this is not a bad contact problem.
I don’t have mSATA card, only 2 stock Wi-Fi cards.

All I can suspect is a power adapter. I sent only the router to Turris, without the power adapter, which could be faulty and can’t supply sufficient current and does not reliably work for me.

The exact same is described by @ssl, @opotonil and @Filip on Dec 2016:

The ticket contains all the logs and other information.

It has been stated before, that this is a known bug (and TO hardware could be replaced by support to resolve it). Have a look here: Omnia 3.10 disappeared Wi-Fi

I read this topic, but I sent the device to Turris already, got it back with the same problem.

The 5GHz card may be faulty or overheating.