I’ve had it for a couple of months, working fine.
This afternoon, the HDMI just stopped working.
It’s as if the Desktop went to sleep, but now can’t see any wakeup signals (mouse movement, KB) - even though the mouse & KB are clearly working.
I can still login via SSH.
Full details here:
https://www.rs-online.com/designspark/rock-4c-hdmi-stopped-working
Is it broken? What other tests can I do?
Dumb question; Did you try the other hdmi connection ? I have had these flip which port is active.
Yes - see the linked post.
Smarter people than me may have better suggestions, but I would use xrandr to send screen through the other port as long as you have an ssh connection.
I had never tried the other port before - should it “just work”? Should I be seeing something on it anyhow?
But none of this answers the primary question of why the 4K port has stopped working - and what to do about it.
As in this: https://wiki.archlinux.org/title/xrandr ?
More specifically: https://wiki.archlinux.org/title/Multihead ?
Update (from the DesignSpark thread):
It had been going through an HDMI switch. Removing the switch and connecting direct to the monitor, it works again!
So that leaves 2 questions:
How come it was working fine for a couple of months, and then just stopped?
How to diagnose what’s going wrong when using the switch?
Note that other devices (a Windows PC; a Raspberry Pi) still work fine through the switch.
Somebody else having trouble with the HDMI output from a Rock Pi 4:
maybe more: