Raspberry Pi 4 not working with NexDock screen

[penguintutor]

Has anyone got the Raspberry Pi 4 working with the 1st generation NexDock (2nd generation expected in a couple of months time)?

If so what settings are you using on the Pi?

When I try the screen is being detected (as the screen goes brighter and does not time out), but nothing is displayed. No colour splash or desktop.
The Pi works fine when I move the cable from the NexDock to a TV. The NexDock works fine with older models of the Raspberry Pi (although not tried with the latest Raspbian except using a Pi 4).

I have tried HDMI force (not 4K). I'm guessing it may be due to an unsupported resolution but if I try and use the resolution changer GUI I get an RandR index out or range error. I'm thinking I may need to start manually configuring different HDMI modes until I get a setting that works, but wondering if anyone has already gone through this and found the best settings to use?

[penguintutor]

After a lot of work trying different configurations I finally found a working solution. Not only did I have to find a suitable resolution, but I had to disabled the edid from being read from the screen.

These are the entries in my /boot/config.txt for anyone else that has similar problems.

Code: Select all

hdmi_ignore_edid=0xa5000080

hdmi_group=2
hdmi_mode=86

hdmi_force_mode=1

This provides a resolution of 1366x768

[mikeyp]

After a lot of work trying different configurations I finally found a working solution. Not only did I have to find a suitable resolution, but I had to disabled the edid from being read from the screen.

These are the entries in my /boot/config.txt for anyone else that has similar problems.

Code: Select all

hdmi_ignore_edid=0xa5000080

hdmi_group=2
hdmi_mode=86

hdmi_force_mode=1

This provides a resolution of 1366x768

Sorry to necro-post but I just wanted to add this is the only thing that fixed this issue for me on the Pi4. It can indeed do 1366x768.

I still don't get the rainbow screen but once it boots into Raspbian it's fine.

[penguintutor]

It's worth noting that this only applies to the original NexDock. The new NexDock 2 is now available which is very different from the first model.

As far as I've tested the new NexDock 2 works out of the box with all current models of Raspberry Pi without need for any special configuration on the Raspberry Pi.

See http://www.penguintutor.com/news/hardware/nexdock2