Encountered this the other day so I made fresh install to track down the issue.
I was able to reproduce it thusly:
- Fresh raspberrian install
- full install of pimoroni unicornhathd and unicornhat from github.
- run unicornhatHD demo - works fine
- run unicornhat code (any?) - throws no error but nothing on display (as expected)
- run unicornhatHD code (any) and nothing displays - no error, nothing
Reboot doesn’t fix it. Re-installing unicornhatHD github doesnt fix it.