"It lights up, starts the spinning and then just stays lit after a few rotations (3 of 5 columns are lit). The “Show Off” button is no longer available"
Then the following procedure should unbrick you:
- Disconnect the siren
- Click “Upgrade Firmware” from the obscure button in the toolbar next to “Siren”
- Select the upgrade file
- Click “Upgrade”
- Wait until the text below the progress bar says “Upgrading…”
- Plug in the device before it times out (you’ll have about 10 seconds)