No HDMI output with RPi 4 using HDMI panel mount cable

Hi all! I bought the HDMI panel mount cable from Pimoroni, but unfortunately HDMI does not output through it with my Raspberry Pi 4.

The extension cable works fine connected to my laptop, and to a Raspberry Pi Zero W.

The Raspberry Pi works fine connected directly to the monitor using a HDMI-micro HDMI adapter.

I’ve also tried the extender on another Raspberry Pi 4 (running LibreELEC), with the same results.

My config.txt has had these lined edited:

hdmi_ignore_edid=0xa5000080
hdmi_group=2
hdmi_mode=81
config_hdmi_boost=11

I later found out that config_hdmi_boost isn’t supported on the Raspberry Pi 4 anyway!

I’ve also tried just setting hdmi_safe=1.

And to confirm, I’m using the HDMI0 port.

Does this HDMI extender simply not support the Raspberry Pi 4?

Happy to say that with the Pimoroni Pirates correctly worked out that the problem was not the panel mount adapter, but the micro-HDMI adapter I was using. If anyone stumbles on this issue, make sure you’re using a good one!