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Any known issues regarding AC2900/RT-AC86U 2.4 GHz radio malfunction?

Discussion in 'Asuswrt-Merlin' started by othersteve, Apr 24, 2018.

  1. othersteve

    othersteve Occasional Visitor

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    Hey guys,

    First post here (done plenty of reading -- hopefully enough). Around 2 weeks ago I replaced my older RT-AC1900/AC68U router with a new AC2900/RT-AC86U router and immediately flashed the latest stock firmware followed by Merlin's latest (384.4_2). The behavior I encountered was rather bizarre: after some arbitrary amount of time, the 2.4 GHz radio would stop broadcasting, and all clients would disconnect. Occasionally it would come back, but thereafter, no intranetwork access between clients was possible (only internet connectivity -- that's it).

    I tried resetting to factory defaults, reflashing multiple firmwares (including the stock ASUS firmware for a few days), but the problem persisted. Today I'm returning the device as I'm fairly convinced that it (hopefully) may be a hardware issue. Radio temps were in the 40s and CPU was in the 70s C if that's of any assistance to anyone (but my 68U runs at 50s/80s constantly, so I doubt it's heat-related).

    My question is: does anyone else have experience with this sort of behavior from this unit? I run a tech consulting company from my home and I really do need rock-solid operation, which my RT-AC68U has been giving me for years now (I just wanted a stronger 5 GHz signal, hence the upgrade). Should I simply replace it with another AC2900/RT-AC86U and expect better results from the next one?

    FYI, my RT-AC68U is running 380.70 Merlin. I'm a little bit afraid to make the jump to the newer branch thanks to the consistency I've seen out of 380 and below. Maybe someone can set my mind at ease there as well ;-)

    Thanks so much for any insight!
     
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  3. Mojolacerator

    Mojolacerator Occasional Visitor

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    I've been running an AC86U(2 months or so) and am always running the pre-beta test builds, have had zero issues.
     
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  4. Treadler

    Treadler Regular Contributor

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    +1
     
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  5. othersteve

    othersteve Occasional Visitor

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    Really appreciate the replies guys. If you don't mind my asking, roughly how many wireless clients do you run on average in these environments? I think mine is between 12 and 15 2.4 GHz clients on average at any given time.

    If no one else has seen such issues, perhaps I'll simply order another of the same router then!
     
  6. bearever

    bearever Occasional Visitor

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    Try downgrading to 384_3. I have seen number of posts that 384_3 works better with 2.4Ghz.

    Make sure you do a initialize after flashing to 384_3 and reconfigure everything from scratch.
     
  7. eastavin

    eastavin Regular Contributor

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    If you prefer rock solid I would stick with 380.70 for say 4-6 months and then reevaluate what next. I have tried the 384 series and did not see too many quirky things until 384.4_2 on a 68U ver C1. In that case odd things started happening several times a day with the wireless like all communication would cease for no obvious reason for a few minutes and then come back and there would be no log entries. There were also other things like certain setup changes would not take unless you click apply twice for some features or reboot for others where no reboot is called for. So I went back to 384.4_0 and the problems subsided. I am going to stay with this one a while and skip _2. There are between 8 and 15 clients running here depending on the time of day-- you asked.
     
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  8. jeff3820

    jeff3820 Regular Contributor

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    We have about 10-15 clients on 2.4 as well as 5-10 on 5 GHz. No issues on the 86U running 384.4_2. I also run a 68U with 384.4_2 and it has also been rock solid.
     
  9. othersteve

    othersteve Occasional Visitor

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    You guys have been extremely helpful -- I truly appreciate you taking the time to reply. I will order another 86U for now and attempt to swap out (using 384.4_0) while the 68U is still working well. If this one also gives me issues then I'll return it and stick with the 68U perhaps until later on down the road.
     
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  10. othersteve

    othersteve Occasional Visitor

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    Hello everyone,

    Well, I recieved a replacement unit today, and it may be hard to believe, but I'm still experiencing the exact same puzzling behavior -- seemingly regardless of which firmware version I choose.

    What happens is that the router operates normally (quite admirably!) for a few hours, and then suddenly, without warning, the 2.4 GHz radio ceases to broadcast and all clients are subsequently dropped. I have no idea what might be leading to this behavior, but what I do know is that the RT-AC68U that I have had in place for years leading up to now has not experienced any such problems.

    I suppose I have little choice but to revert to my older router and perhaps consider other brands (which I'd hate to do, not least because of Merlin's amazing involvement in firmware customization/development for these ASUS models) unless anyone has any other suggestions here. I also feel rather hesitant to recommend this router to my clients (in spite of the positive reviews and feedback that I've seen in many places).

    Thank you again for the assistance. If anyone has any final suggestions I am happy to try and provide whatever information might be deemed useful.
     
  11. Blinkyz

    Blinkyz Senior Member

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    380.70 is not made for rt-ac86 , just for info ;)
     
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  12. othersteve

    othersteve Occasional Visitor

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    Yeah; that's the version I'm running on the old 68U. It's never given me any issues and I'm reluctant to make a move as a result of that.
     
  13. Odkrys

    Odkrys Senior Member

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    Try to disable MU-MIMO, Beamforming and to enable Reducing USB 3.0 interference in 2.4Ghz.
     
  14. Treadler

    Treadler Regular Contributor

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    Location:
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    My 2.4 rock solid here.

    2.4 settings:
    Channel width manually set to 20 MHz.
    Mu-MIMO disable.
    Universal Beamforming disable.
    Airtime fairness disable.
    Roaming assistant disable.
    Reduce USB 3 interference disable.

    All these have been recommended at one time or another in this forum.
    Might be worth trying?
     
    Last edited: May 2, 2018
  15. othersteve

    othersteve Occasional Visitor

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    Perhaps MU-MIMO is the reason. I have all of the other settings configured as suggested already.

    When I have a slower moment I'll swap out the routers once more and see if it helps at all.
     
  16. lukaszzsch

    lukaszzsch Regular Contributor

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    I am experiencing The same problem with my own 86u.

    i have notifed that such behaviur occured twie after installing utop at entware, but it can’t be connected i see...

    Strange...
     
  17. zoggy

    zoggy Occasional Visitor

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  18. othersteve

    othersteve Occasional Visitor

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    Is it possible to flash a new RT-AC86U back to 380 firmware? Apologies for the ignorance, but tech consulting is a lot like medical science you know; we're good at our areas of expertise but only tangentially useful in others ;-)

    Thank you!


    Edit: Looks like there is no 380.xx release for the RT-AC86U. So, return/wait it out is the only option I suppose? I'm really leaning toward another return in light of this... :-(
     
  19. lukaszzsch

    lukaszzsch Regular Contributor

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    Try to flash 384.4.2 again, then do a long power cycle(at least 15 minutes unplugged) then make initalization and set your router ul again. It seems to be a well-working solution.
     
  20. lukaszzsch

    lukaszzsch Regular Contributor

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    Your answer is not optimistic but makes me relaxed. I bought my device in China and already thought that 200$ is wasted because of router fail.
     
  21. othersteve

    othersteve Occasional Visitor

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    All right, I've swapped it back into production now running 384.3. Did an initialize and set everything up again. 23 clients connected total currently, various interfaces.

    2.4 GHz channel width is still set to 20 MHz; the only other thing I've done differently this time is to disable MU-MIMO and enable Reducing USB 3.0 interference on 2.4 GHz as well. We shall see what results. If this doesn't work then I've got multiple routers to return because I bought some to install for clients next week as well (and I can't put this thing into production for clients if I can't trust it to be rock-solid).

    Thank you for the help as always. I will report back with results.
     
    Last edited: May 3, 2018
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