When the controller is absent
Connect the Stream Deck with its own cable, to a port the maker supports. Test a direct connection before a hub. Check the exact model’s supported operating systems and port restrictions; one model’s requirements don’t apply to another.
If the application sees the device but OBS does not respond, the USB path is not the only suspect. Check the OBS plugin and its selected target instead of reconnecting every peripheral.
When a key lights but does nothing
Open the selected profile and inspect the key’s action. Check that the scene or microphone name still exists in OBS. For a hotkey, check the same shortcut in the target application and whether another app has taken it.
Configure one known scene action using the Stream Deck setup guide. Test it before importing a larger profile or chaining a Multi Action.
Restart and test the action
Restart the target application and Stream Deck software, then press the same key. Check the real scene or microphone state. If the action fails again, record the exact model, application and action name for the maker’s support route.