Audio Systems: Home stereo popping sound, xm radio, best buy

Question
We're having a problem with a popping sound and can't locate it.  While playing CDs or records, the music randomly and occasionally (or often, and sometimes never) cuts out with a popping sound.  When no components are being used, but the receiver is on, I can hear an intermittent pop, like an electrical sound.

We think it may have started after connecting a wire that some tween at Best Buy recommended for plugging in the car's XM Radio receiver.  Someone recommended a surge protector for the outlet, but that hasn't solved the problem.

I really hope you can help pinpoint or even solve this for us!  The frustration is enormous; I'm learning to leave the room when my boyfriend starts fiddling with the stereo.  

Here are our components:
Sony STR-DE515 A/V control center
Magnavox CDC 552 changer
Denon DP-300F turntable
Bose 201 Series IV Direct/Reflecting speakers

Thank you so much!

Answer
Popping or static of some sort with components is not generally a cut and try problem. Without my physically hearing exactly what you hear, I can't apply my experience to answer. I will start by asking you to disconnect all inputs to the receiver and turn up the volume to hear if the popping is still there. That will tell you if the problem is with the receiver. You should check the reciever switched to all inputs including the Radio. Get back to me as to what the test results showed.