Solution to 5Ghz not showing after firmware upgrade

[Rohit]

I absolutely adore the firmware but every single time i upgrade the firmware and reboot, the 5Ghz radio does not come up. I have to hard reset and lose all the settings and reconfigure again (painful with the open vpn especially). I know this problem has been reported for ages but I have never come across any solution that works, can some one please correct me if and suggest what might be wrong (I have a RT AC66U model), alternatively would you suggest any other Asus router that has no issues like i mentioned above?

Many Thanks

 

[ColinTaylor]

I'm not aware of this being a known problem with the RT-AC66U (do you have any links?). I know there are reports for some of the more recent models, but they have different hardware.

Just a thought; How long are you waiting for the 5GHz radio to come up? It will take at least 60 seconds longer than 2.4GHz if DFS is enabled, possibly longer.

 

[Rohit]

I see quite a few links https://www.google.com.hk/search?q=rt-ac66u+5ghz+not+working sorry. I have left the router as it is and waited beyond few hours but didn't help. Reading upon other threads which has same issue, it looks like this is a hardware issue https://www.snbforums.com/threads/rt-ac87u-merlin-380-69-5ghz-wlan-problem.42867/, wonder if the same problem would exist with AC66U as well?

 

[ColinTaylor]

Reading upon other threads which has same issue, it looks like this is a hardware issue https://www.snbforums.com/threads/rt-ac87u-merlin-380-69-5ghz-wlan-problem.42867/, wonder if the same problem would exist with AC66U as well?

That wouldn't apply to the AC66U, the AC87U is odd because it uses a separate Quantenna chipset for 5GHz instead of Broadcom.