Hi guys, A week ago I pickup this neat looking little Marantz stack, with tuner and amp in excellent condition but the cassette deck not working. The model 5000 not only needed new belts, but I had to take the whole transport mechanism apart to clean off the harded old grease. Eventually I got everything working fine, but now this problem has popped up: There is an annoying hum from the speakers when I connect the deck to the amp with RCA connectors. Sounds a lot like ground hum. Both units have european plugs with ground so I can kind of see this.. Playback and recording is good, no problems there. But: when I hook up the deck by the DIN connector, the hum is gone! Great! Playback works just fine, but when I try to record, all I get is this very high pitched screeching from both channels.. The play/record switch has been very thouroughly cleaned btw. DIN to RCA cables just give me the ground hum again. So my question is twofold: - Is there any way to get rid of the ground hum other than to bypass the grounding on the plug? -What could be causing the high pitch noise ( and no signal) when I try to record over DIN? The DIN cable itself is an audio one, bought through the Philips audio forum a while ago. Any help is appreciated, thanks in advance.