I picked up a harman/kardon DC5300 dual cassette deck recently. Nice and clean except for a few spider webs. This unit has a problem accepting commands from the front interface; when a tape is loaded the stop/play/ff/rw buttons do not do anything. So I sprayed deoxit d5 all over the insidey parts and let it dry. Then I loaded a tape and was able to play/ff/rw at will. Was very happy. But then 10 minutes later the same problem came to fruition; with a cassette tape loaded into the deck none of the buttons (play/ff/rw, etc.) did anything. So, my question is: when most of the button commands of the DC5300 do not work what should I do? Remove the front plate and dexoit?