You can update your xbox controller firmware without an actual xbox.
Recently Microsoft has released new update to address the controller disconnection bug. So its highly recommended for you to go ahead and see if your controller need an update as well!
In addition, the XBOX Accessories app also allows you to test all the buttons. This can be very handy if your controller acting weird.
Download here: XBOX ACCESSORIES APP
WHERE TO BUY?More premium XBOX accessories: