A:AnswerThat's a vague question, so here's a vague answer. Yes, certain control can be done, as long as a mac-compatible IR receiver (usually USB) is installed.
A:AnswerIf the Harmony has been programmed correctly for your TV, and you have setup the activities correctly, then you need to press the help button. The remote will go thru a series of questions to correct, and learn the problem. If the activity is not working as expected, always press the Help button.
A:AnswerWorks great with Xbox One, can't imagine it would support xbox and not PS4. I would definitely google it first though. They have a great compatibility checker on their website.
A:AnswerCan't answer your question specifically, but Logitech has a compatibility support page. Just enter your model number and it will tell you if it's compatible. https://support.myharmony.com/en-us/compatibility
