The link has instructions for removing the amp foe fuse.
If you have already disconnected the battery then this is likely not the problem.
Is the volume low for all sources? Am/FM, SXM channel (preview if you don’t have a subscription), USB or Bluetooth?
Does it make a beeping sound when the buttons are pressed?
you can check the speaker output: go to factory settings… press and hold the home button, while it’s held press the tune/scroll button twice and release.
in the factory settings, select the screen for Ausio Control. Then press the speaker control button. Be prepared to turn the volume down just in case… it can be loud. It should circulate through the speakers. To stop the control, press the speaker control again. To exit, press the “Home” button at the top of the screen (the “Home” button on the side will not work to exit)
See attachment 501789
