My elderly relative who is blind has used Sirius radios in his home for 15 years. We recently got a new model Onyx EZR and Speaker dock SXSD2. He has described a loud popping sound he thinks could be an electrical short. Happens intermittently. We are hours away and no one has been with him when this happened that could look at the screen for any information. Anyone else using this setup that could assist with an explanation?