I have an original Unicorn Hat that I have used without problem in the past. I dug out my Pi 2 that still had it on and the original SD card in (not used for a while sadly) and all the LEDs came on in a diagonal rainbow on boot and stayed on. Running the existing scripts did nothing. The install hasn’t been updated or changed in any way.
Next I tried a clean install of the very latest Raspbian on a new card. Booted up and updated, then manually installed the Unicorn Hat bits with PIP according to the Pimoroni instructions (sudo pip install unicorn hat - the other dependencies are already there). Unfortunately although the test scripts run with no errors none of the LEDs light. I have tried detect.py which wrongly identifies it as a pHat because it thinks the height and width differ, but even changing the unicorn.set_layout to unicorn.HAT instead of unicorn.AUTO doesn’t help.
To make sure everything was properly installed I have now run the \curl command to download and run the installer, but that just confirmed everything was already setup correctly and downloaded the examples.
So far my Google Fu hasn’t located any more detailed diagnostics to work out what is and/or isn’t working properly. Has my Unicorn Hat gone the same way as my first Piglow and started getting unreliable? Does anyone have any ideas?