Pi 5 Wi-Fi Die, Retry? Part 2 of the Unyielding Saga of Troubleshooting Raspberry Pi 5 Wi-Fi

5 CommentsRaspberry Pi 5, troubleshooting, ,

In the previous post, I confidently declared, “no more Raspberry Pi 5 Wi-Fi Problems.” As it turns out, I spoke too soon. I was not done Troubleshooting Raspberry Pi 5 Wi-Fi.

After creating and running the previous systemd scripts, Wi-Fi began working again. It worked, as all things everywhere, throughout all time have done, until it didn’t anymore. I double-checked the scripts and was able to rule out any additional power management problems. iwconfig revealed that wlan0 was down and sudo ifconfig wlan0 up would not work to revive it. The only thing that would get Pi 5 Wi-Fi working again was to turn the system on and off. Eventually, even that stopped working. The nuclear option analogue of “have you tried turning it off and on again” is to unplug it and plug it back in again. That worked, likely because some components (especially Wi-Fi/Bluetooth chipsets and USB controllers) retain state across soft reboots due to residual charge. A hard power cycle fully drains capacitors and forces the hardware to reinitialize cleanly.

Pi 5 Wi-Fi Die, Retry? Part 2 of the Unyielding Saga of Troubleshooting Raspberry Pi 5 Wi-Fi

This meant the problem was most likely an initialization error. Logs revealed that the failure wasn’t related to firmware or kernel issues. Running vcgencmd get_throttled returned 0x0, indicating that it wasn’t a power source problem, either. The best explanation for Wi-Fi failure at this point was a resource conflict, a theory supported by the fact that the issue had progressively worsened over time.

Pi 5s typically use Broadcom chipsets for their Wi-Fi, often BCM43455 or BCM43456. This chip is also responsible for Bluetooth (you can probably see where our Raspberry Pi 5 troubleshooting is going). While they use different interfaces (BT uses UART, wifi SDIO), they still share some internal processing and power resources. We can mitigate Bluetooth’s resource usage by reassigning it from UART to mini-UART (this has the potential of solving USB resource conflicts as well). Here’s how:

sudo nano /boot/firmware/config.txt

Add the following overlay (before any [cm4] references):

dtoverlay=pi3-miniuart-bt

Ctrl+x to exit, Y to save, and Enter to accept the default file name.

sudo reboot

And that should be it! Both Wi-Fi and Bluetooth should be functional, as well as any USB peripherals.

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5 Comments

  1. Florian Lehmann

    Reply

    I cannot thank you enough!!! this was what finally fixed my issues! You’re a literal godsend!

  2. Craig

    Reply

    Hello!! I actually spent most of my life as a Computer Tech (Since MS-DOS 4.22) self-taught, but when I was old enough to start working I did get my A+ Certification along with a few MS Certs and started working towards the Cisco Certs when I got sick almost died and long story short i’ve been out of work for about 10 years now and I was a pretty good tech plus I loved what I did which is always a plus and even though i’m lagging quite a bit in my tech skills since I hardly use them anymore my troubleshooting is still pretty good and so I did quite a bit of troubleshooting my issues before finally realizing it was the Raspberry Pi 5.

    My Home Network – Cox Communications ISP
    -Panoramic Gateway (Wireless Router/Cable Model)
    *Default the SSID/WIFI is combined 2.4GHz and 5 GHz using same name, but I split them to their on SSID MyWiFi (2.4GHz) and MyWiFi (5GHz).
    -Lenovo (Windows10Pro) – My HTPC/Media Server (Wired; Shielded Cat6 Ethernet Cable)
    -Apple TV 4K (Wired; Sheilded Cat6 Ethernet Cable)
    -Legion 5 Laptop (Wired; Shielded Cat6 Ethernet Cable)
    -Playstation 5 & XBOX 1 (Both Wired; Shielded Cat 6 Ethernet Cable)
    -And Finally-
    -Raspberry Pi 5 [Libreelec/Kodi] (Wired; Shielded Cat 6 Ethernet Cable)
    -I have a bunch of wireless smart devices, Samsung Smart TV’s, Apple iPhones & iPadPro’s etc…
    **The Problem being caused by the Raspberry Pi 5 was for some reason the Wifi-5GHz network was the only one mostly effected. Any devices that connect to the 5GHz WiFi was getting disconnected, sometimes the 5 GHz Signal itself was no longer broadcasting or at least I was able to see the signal regardless of which wireless devices I was using. It comes back and sometimes your able to stay connected but the xfer speeds are chaos, sometimes it’d test fine then a few min l8r it’d drop down from 6-700 Mbps to like 12. As far as the 2.4 GHz WiFi that one worked no problem! So off the bat I originally figured it was the Gateway – since it always worked no problem before but even after swapping out my Panoramic Gateway for a brand new one from Cox after finishing setting it up bringing everything back online not even 15min after same issues with 5GHz all over again.
    -I even ran a spectrum analyzer throughout my apartment to map the signals even borrowing a friends high end SpecAnalyzer which basically had the same results as my laptop & rooted samsung device set for this type of stuff – it did have a lot more details and better range more options but regardless the wireless signals throughout and around my apartment are actually pretty good but I already figured but covering bases. Even made slight changes to the 5 GHz channel so it’s basicaly the only device using that freq…
    So I did a lot more troubleshooting but if I listed everyting this msg would be really long and it’s all basically just a waste of time to read – point was I basically ruled out just about everything else.
    Still didn’t really make sense to me because the RBPi5 is on network via Ethernet and I even switched off the Wireless Adapter on the Raspberry Pi so at this point I’m completely lost. There was some other issues with the RBP but since I just bought a new microSD, downloaded the latest Raspberry Pi Imager, downloading the latest Libreelec/Kodi OS imaged onto the new SD and installed into the RBP all the other issues I mentioned was resolved; EXCEPT for the same damn issues effecting the 5GHz Wifi.

    So I tried to keep that a short as possible trying to only mention important facts but because of one of the meds I take for narcolepsy sometimes I’ll tend to ramble on so I apologize in advance.
    I read your original post w/fix as well as 2nd and even seen it’s helped others but for some reason I’m having trouble connecting, if I understand your RBPi was connected to the network via WiFi so I wonder if it’s still the same issue. I’ll have to go over your posts again and see if i can try to follow making the same changes to see if that might possible resolve my issue once I’m able to focus long enough for it to connect instead of reading the words and having the meaning bounce off my brain.

    If you or anyone does take the time to read this post I thank you for your patience and hope that I didn’t ramble too much with topic jumps (when it’s really bad), but either OP or anyone else that completely understands the problem I’m having as explained above (i hope) and also fully understand the solutions OP ran that resolved his issuses and know if the solutions offered here might help me please feel free to respond or msg me – I will greatly apprecaite it.

    Thanks again to anyone that has taken the time to read my long response and even having the patience to read it through I thank you, and apprecaite any tips or solutions you may have to offer.

    -Craig-

    • admin

      Reply

      I too am out of work due to illness! Here’s some stuff:

      Despite being wired, the Raspberry Pi 5’s onboard Wi-Fi (or even Bluetooth) may still be interfering with the 5GHz signal, likely due to radio frequency leakage or a firmware bug. Raspberry Pi 5 users have reported similar issues where the Pi’s internal components interfere with nearby 5GHz Wi-Fi, even with Wi-Fi turned off.

      Here’s some stuff you can try:

      1. Add the following to /boot/config.txt to fully disable the onboard wireless and Bluetooth:

      dtoverlay=disable-wifi
      dtoverlay=disable-bt

      Then reboot.

      2. Use a Ferrite Bead on Ethernet
      If shielding is an issue (ground loop noise or EMI), try adding a ferrite choke (clip-on or built-in) to the Ethernet cable connected to the Pi. This can reduce unintended RF emissions. I don’t know how much this will help if your cables are already shielded, but it’s worth a try.

      3. Try a USB-to-Ethernet Adapter
      If the built-in Ethernet hardware is interfering, use a USB 3.0 to Gigabit Ethernet adapter instead and disable the onboard Ethernet (eth0). It sounds crazy, but this worked for some users in forums experiencing similar 5GHz disruptions.

      4. Try Another OS Temporarily
      Boot Raspberry Pi OS (Lite) from a spare microSD to see if LibreELEC/Kodi-specific drivers or services are causing interference.

      And finally…
      5. Build a faraday cage for your pi
      A cardboard box that’s large enough to thwart thermal issues and lined with tinfoil will do the trick. There should be some ventilation. Of course, the Pi should already be in a case so that there’s no chance of shorting against the foil. And the foil must be grounded, otherwise you’re just reflecting RF or turning the foil into an unintentional antenna.

      LMK if any of that works, I might do a blog post on it!

  3. Ralph Angenendt

    Reply

    Hi,
    I really do hope that this is the final puzzle part to make my raspi 5 behave on wireless.

    One thing though – depending on age of the distribution, the overlay “pi3-miniuart-bt” has been renamed to “miniuart-bt” as it is not pi3 specific – see https://forums.raspberrypi.com/viewtopic.php?t=360821

    Would be great if you could reflect this in this post.

    Now fingers crossed, I am going to reboot the pi.

    Thanks!

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