Picked up this cool Sansui Six at an estate sale. The owners son was pretty sure his dad had bought it new. When I first powered it up with FM there was only a faint sound from the speakers. After a few minutes of playing with the knobs it came to life. I dexo'd the input and speaker selectors and all seems to be well. I am little concerned about a slight pop on the left channel at power down. That said, I am pretty happy with this little receiver. Anybody know what the crud is inside the cover?