Raspberry Pi 4 Bug – Wifi stops working after using a high screen resolution
Many users of the Raspberry Pi 4 have been reportedly suffering from Wi-Fi connection problems after setting the display screen resolution to 2560 x 1440.
With the big Raspberry Pi community, users have taken the issue to online troubleshooting forums and Raspberry Pi support forums for solutions and workarounds. An obvious solution and workaround currently would be to switch to a lower resolution while the root causes for the bug are not found yet.
There have been several reports on the issue and based on Android Authority, Raspberry Pi head Eben Upton says that the problem may be due to the user’s HDMI cables.
Hard to know what the problem is from the blog post (sic), but this is exactly what I’d expect if someone was using poorly shielded HDMI cables. A poorly shielded cable radiates ~20dB higher than a properly shielded one. I’d be very surprised if this is a hardware issue with the Pi itself.
Eben Upton as per Android Authority
If you are also facing the same problem, you can try switching and changing your HDMI cables to see if it solves the problem.
A software developer, Enrico Zini have also reported the same issue while working on a digital signage box based on the Raspberry Pi 4.
One full day of crazy debugging, and the result is that if the Raspberry Pi 4 outputs HDMI at a resolution of 2560×1440, the WiFi stops working.
Enrico Zini
Enrico Zini tried to reproduce this Raspberry Pi 4 bug after a guest mentioned about screen resolution. He manages to reproduce it through a few circumstances:
- on both microHDMI outputs
- with two different cables: one with a microHDMI to HDMI dongle adapter; one direct microHDMI to HDMI. The latter is the one I bought in the Raspberry Pi Store in Cambridge together with one of the Pi 4 units.
- with three different RaspberryPi units
- with 4 different power supplies: one rated at 2A, one rated at 3A, one rated at 3A bought in the Raspberry Pi shop in Cambridge, and a laptop USB-C charger
- with stock Raspbian Buster Lite
- with stock Raspbian Buster
- killing every process in the system, starting the network manually with
wpa_supplicantanddhclient, and starting X manually withsudo X - with two different SD cards
- connected to an AP some meters away, and connected to a phone hotspot next to the Raspberry PI
Users have also been suggesting that this problem can be due to power consumption, interference from accessories, software, etc but no one really knows and clear of what is really causing this bug to happen.
What can you do?
Meanwhile, as no solution has been officially given by the Raspberry Pi Foundation, it will be best to run your Raspberry Pi at a slightly lower resolution if you are suffering from this issue too.
You can also try switching out your HDMI cable with another one and see if it works.
Updates
To look out for updates on this issue, you can check out
- The discussion thread on Hacker News
- Raspberry Pi official Troubleshooting forum thread
Are you suffering from this issue too? Leave a comment down below where you guys can discuss about it too!
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