I am hoping someone may be able to assist. I picked up Beocenter 7000 along with the SC-70 cabinet in Rosewood. The turntable, receiver, and external inputs all work great. The cassette deck was not functioning. I replaced the belts, which had turned to sticky black goo. The mechanism of the cassette is now functioning perfectly. At first I had audio from the left channel and just a loud hum from the right channel. A little later, I had no audio signal. Instead, there is just hiss or rumble. It is as if it is picking up the movement of the tape across the head but not the audio information. Any suggestions are welcome!