AC66U - 5GHz radio death?

[adampk17]

RT-AC66U with 380.68 Merlin release.

Months ago the 5 GHz radio stopped working if the channel bandwidth option chosen was either of the options that have 80 MHz in them. 20 MHz and 40 MHz worked fine, 80 MHz and 20/40/80 did not. The SSID could never be found.

Last week the router started restarting itself every couple minutes. After much troubleshooting, including factory resets, opening the router, cleaning the dust out, and firmware recovery, I've determined that if the 5 GHz radio is turned off the router behaves normally again.

Anyone seen this with this model before?


Thanks in advance

 

[Arbores]

I have a very big problem with 5 GHz radio. After update 380.68 5 GHz death. On page "Site Survey" - "5 GHz radio is disabled - cannot scan that band!", but lamp 5 GHz on RT-AC66U - work.

 

[adampk17]

Arbores - on the Professional tab of the 5 GHz radio, there is an option to disable the radio. Have you checked that setting?

 

[Arbores]

Arbores - on the Professional tab of the 5 GHz radio, there is an option to disable the radio. Have you checked that setting?

Yes, I checked. But it did not help(

 

[bnhf]

I have a very big problem with 5 GHz radio. After update 380.68 5 GHz death. On page "Site Survey" - "5 GHz radio is disabled - cannot scan that band!", but lamp 5 GHz on RT-AC66U - work.

I was having the same problem with my RT-AC66U, and also thought it had something to do with the 380.68 update. However, it was my power supply -- I had been using one that had a slightly loose fitting barrel connector on the router side. The router seemed to be working fine except for the 5GHz radio. I switched back to the original power cord and 5GHz instantly returned!

 

[Arbores]

I was having the same problem with my RT-AC66U, and also thought it had something to do with the 380.68 update. However, it was my power supply -- I had been using one that had a slightly loose fitting barrel connector on the router side. The router seemed to be working fine except for the 5GHz radio. I switched back to the original power cord and 5GHz instantly returned!

Gracia! Thank you! Дякую!
It really helped! The power cord did not have a sufficiently tight contact. I pulled it out and returned it back - and it worked out!

 

[DanielF]

Solution also worked on RT-AC68U, after updating firmware 5G died, as per suggestion in this post I umplugged the power for a couple of minutes and then plugged it back in, checking that it was secure. 5G working perfectly. Not sure if it was merely the fact of turning it off and on that did the trick, but it is now working.
Thanks

 

[ajay22]

I created an account just to hop on this old thread and say that the "unplug" method worked for me also.

I had a brief power outage this morning which killed the 5GHz radio on my AC66R (same as AC66U). I tried reboots and factory reset and normal power cycle using the power button and none of those methods worked. I unplugged the power cable both from the router and from the wall (and allowed the power brick to discharge and the light on it to go out). When I plugged everything back in it just worked like normal. No idea how/why that cable became fussy, but this fixed it.

I will also note that I was curious about whether the power outage affected the router via other devices. So I unplugged everything, all ethernet cables from the router and the power cable at both ends. I also waited 30 minutes in this unplugged state before plugging everything back in. Why 30 minutes? I saw that in another thread.

Anyway. To anyone looking for a "5GHz not working" fix, try the unplug method.

 

[a5m]

Recently had this issue with our RT-AC66U that we had set up as a Repeater. Updated to latest Merlin 380.70 and 5GHz was disabled. Trying the above method didn't work. After some Googling came across a thread on tomshardware with the following instructions that worked:

Switch off the unit at the back, wait 10 seconds, depress reset button and then switch unit back on. Keep holding the reset button for 10-15 seconds. The Blue Power Light LED will blink slowly. Let go of the reset button and the Power light will continue to slowly blink. Let it blink for another 30 seconds before turning the unit off via the power button. Wait 10 seconds and then turn the unit back on. Wait for unit to restart and both 2G and 5G lights to illuminate.

 

[masl73]

Solution also worked on RT-AC68U, after updating firmware 5G died, as per suggestion in this post I umplugged the power for a couple of minutes and then plugged it back in, checking that it was secure. 5G working perfectly. Not sure if it was merely the fact of turning it off and on that did the trick, but it is now working.
Thanks

I have RT-AC66U and my 5GHz wifi stopped working. The diode on the router was lit, but the software showed that 5G Wi-Fi was disabled. I did various things and nothing helped and I didn't even think that turning the power plug off and on again would work, but it did. Thank you so much for help !!

 

[L&LD]

Welcome to the forums @masl73.

Yes, it is amazing what a simple electrical reset can do.

 

[Viktor Jaep]

I have RT-AC66U and my 5GHz wifi stopped working. The diode on the router was lit, but the software showed that 5G Wi-Fi was disabled. I did various things and nothing helped and I didn't even think that turning the power plug off and on again would work, but it did. Thank you so much for help !!