Hi everyone, I posted this in another forum first and was advised there to try my luck here because there are WM-D6C experts here, I was told. Anyway, I recently wanted to play a cassette on a Sony WM-D6C that hasn't been used for probably more than a decade. However, upon pressing play, nothing happened. I opened up the unit and saw that none of the gears/belts were moving. Also, the motor wasn't moving at all. My first thought was an electrical issue but the voltage supplied to the motor was fine. I manually rotated the motor pulley a few times and, after switching the unit on again, the motor was running by itself again (first time I thought "problem solved!"). However, after reassembling everything and testing the cassette (which sounds fine on a cheap Fisher Price cassette player btw) the sound was very deformed (I'm not very familiar with all the different terms but, based on the description, I would say it's "wow"). Thanks to other posts on this and other forums, I got a few ideas and replaced the following parts (even though none of them looked particularly bad) Main drive belt Counter belt Capstan ring Pinch roller All to no avail: the deformed sound was still there. Now, I'm starting to doubt whether the motor is actually running completely fine or whether there's still some friction going on inside. Another thing I noticed is that, when slightly pushing the motor down during playback (at the side of the pulley), the wow seems to go away. Obviously, it's not straightforward to completely verify this by pushing the motor down (see red arrow in the image below) in a way that it still touches the capstan ring, but there's an audible difference. So, my assumption was then that perhaps the motor is pushing too hard on the capstan. I tried to unscrew the white, nylon screw of the capstan bracket as much as possible but, even then, the motor simply pushes the capstan against the top bracket and the wow is still there. Is this all normal? I suppose there's no way to offset the motor's vertical position more downward? Any further suggestions? Should I try disassembling the motor? I've read on this forum that there should be a tutorial for this. Thanks a lot in advance!
Do you have a W&F measurement screenshot from WFGUI ? The pressure motor spindle puts on the rubber disc is given by the spring tension. If that spring is original, there's no reason to suspect the pressure itself is the problem. Given the motor was not turning at all in the beginning, would check if it spins freely. It's likely the motor needs some lubrication. One other thing to check is the flywheel thrust play: when unit is in STOP mode (motor not engaged on the rubber disc), move the flywheel up/down. You should have very little play, around 0.1mm. If play is high, tighten the screw and glue it in position once correct play is achieved.
Valentin is right on! Everything should be spinning very easily (both motor and flywheel). I've had times when the motor angle to the rubber disc needed adjustment but that (in my experience) is rare, mostly if someone else has fiddled with the unit. A motor not spinning very easily will not give enough torque/power which in turn will produce wow/flutter...
