Logitech Harmony remotes are highly-customizable and can be programmed to operate nearly any function of a home theater system, for example. The remotes include firmware that helps them process the correct commands once a button is pressed and send the signal to the device. If your Harmony remote turns on to a blank screen, you may need to restore this firmware to get it working properly again. The restore process is similar for all Harmony remote models.

How to Fix Harmony Remote Lights With a Blank Screen - 73