RPi 4 HDMI Input Flicker/Blink during 4K Content

#1

First off, annoyed that I had to sign up for a forum to get two questions answered by Little Bird, anyway…

The HDMI cable that comes with the Raspberry Pi 4 starter kit, is it 4K capable?

Second question, has anyone had to send their RPi 4 back due to the HDMI input blinking/flickering off and on (as if changing tv input or plugging/unplugging cable) during 4K content?

I am using Libreelec v9.1.501 (kernal: Linux 4.19.66), I’m a using the power supply provided and it has a solid red light with no flickering. The issue only presents when Kodi on Libreelec is set to resolution 3840x2160@30hz and I play any videos at all. Once the video is playing if I press pause or any button at all the HDMI blinks. No one else on Libreelec forums or Reddit is having this issue and they keep telling me it’s my HMDI cable, I have tried four different cables now and nothing has changed and it leads me to believe I have a faulty RPi. I have also tried different HDMI settings in the config and that hasn’t fixed anything either. Yes I know this version of Libreelec is still in its teething stage but no one else is facing this issue. Any thoughts?

#2

Anyone? I was told I would get a faster response on here… I just replaced my 4K micro HDMI to HDMI and I am getting no display at all using this.

#3

It has been almost 24hrs with no follow up.

#4

The HDMI cable that comes with the Raspberry Pi 4 starter kit, is it 4K capable?

Yes, and unlike kits from other vendors it is sourced directly from the Raspberry Pi foundation. The foundation use high quality parts so it is unlikely the cable is at fault.

has anyone had to send their RPi 4 back due to the HDMI input blinking/flickering off and on (as if changing tv input or plugging/unplugging cable) during 4K content

Not as yet.

The issue only presents when Kodi on Libreelec is set to resolution 3840x2160@30hz and I play any videos at all.

Narrowing down the variables:

  • Have you tried removing any EMF/RF sources that could be interfering w/ the cable?
  • Do you experience the same output across different inputs / outputs?
  • Do you experience the same output across multiple displays?
  • Do you experience the same output on the latest version of Raspbian?
  • Could it be a video codec issue? Is the Pi struggling to keep up with decoding a file?
  • Have you tried modifying the CONFIG_HDMI_BOOST?
  • Better still what does your config file look like? https://www.raspberrypi.org/documentation/configuration/config-txt/video.md

These are the questions I’d ask to try to narrow things down…

#5

I was able to get this running myself whilst waiting for an answer. As a last ditch effort, I decided to wipe the SD card and reinstall Libreelec again, the next step was going to be to true with Raspbian. However the issue disappeared with the reinstall. However, it still does change the fact that the provided cable gave me no picture at all, whereas ones I then had to buy at my own extra expense partially worked (with flickering issue). The cable you have provided still does not work with 4k at all.

In response to what had I tried, I had tried everything you had mentioned there except for using Raspbian, as of at the time I did not want to wipe my install and set it back up again.

Considering I paid for the HDMI cable as a part of the ‘kit’ that I bought, how do I go about getting that replaced?

#6

Hi Mitch,

If you’re certain it’s the cable, you can return it by completing the Raspberry Pi Repair form.

Cheers,

Marcus