Ok, if the volume buttons are not working in device mode, delete your Pyle PSBV600BT, then add it again you will have to edo any Activities that included it. Sync your remote, thenput your 650 in device mode, select the Pyle PSBV600BT and test the volume buttons to see if they work. If they now work, test each of your activities to see if the Volume buttons work as expected. If they don't work in your Activity, log back on to your account, select Buttons, select your Activity and the hard buttons verify that the correct volume command and device are mapped (assigned) to the volume buttons make any corrections as needed. Sync your remote when you are done.