Hello, A while ago I received a WM-D3 with replaced center gear for a decent price. However what the previous owner did not tell me that it has a horrible whining sound and my local audio repair business could not fix it. I opened it up and found out the new center gear makes this noise. The noise can also be heard in the audio during play and recording One of 3 "ribs" also hits the play mechanism which makes me suspect the gear is not properly aligned. Before I disassemble further, what do you guys think what the problem can be? I can take out the center gear but then what would be the next step? I should also note the Walkman came without any oil or grease on the gears so I put a drop of sewing machine oil in but that ofcourse did not solve the problem If allowed I can send a link to a video containing the whining sound Link to the video: https://youtube.com/shorts/vc8CSTaoeoA
Because the sound is so constant, I think the problem lies more with a squealing motor bearing or something similar. The front bearing of the motor is easy to lubricate. I do hear the gear grinding a bit, so aligning it better with the metal disc wouldn't hurt. Especially if the cams on the gear are hitting the play-lift mechanism.
Thank you for the quick reply, I put a drop of oil at the front of the motor and the squealing disappeared but now I'm a bit stumped. It seemed to work fine and I left it for a few hours. Now that I wanted to put everything back together it seems to have developed other issues. In Play the cams now fully hit the mechanism thus stopping the center gear from turning and play won't stay engaged either if I move the mechanism out of the way. I'm not sure if this mechanism triggers auto stop? In FF and Reverse the gear is just barely turning. I'm starting to think the sewing machine oil is not fit for the gears but I'm more confused about the Play mode now not working properly. I've cleaned everything but the motor with 99% alcohol and will do another clean tomorrow to see if it gets better. Just to be extra clear: I dissassembled the motor, capstan/idler + bracket and coil, smaller white gear, center gear top clip, the 2 brackets on top of the buttons and the (cassette) lid. I did not remove the center gear or buttons themselves I've made another video with the issues; https://youtube.com/shorts/ocY_4qJdTD8 Somehow Youtube automatically makes it a short video so sorry for that
It's good that the noise is gone. Your next problem is that oil has gotten onto the motor shaft and the rubber capstan disc. You now need to degrease both the drive shaft and the rubber capstan disc with alcohol so that there is sufficient friction between the two parts. You don't need to take it completely apart. You can get a cotton swab with alcohol in between while the Walkman is running to get the oil out. You may need to repeat this a few times until no more oil comes out of the motor bearing.
Play now seems to work better and almost perfect but FF and Rewind are still very slow so I'll see if I can clean everything I did mess up something else, it's now playing way too fast.. Motor gets 2.68V which makes me believe I somehow damaged CX20084. Could this have happened while only using rechargeable batteries and holding the 'live' board? Or could it be because I tried running it with too much friction? I always thought the chip in these units would be "safe" because the unit only runs on 3V but I might've messed up big time Edit*: I measured pin 15 and it gives 1.99V so that's odd. FG coil measures 716 ohm Q601 measure 1.97 and 2.69v which should be OK (2.3v and 3v per manual) but output is 2.66V and should be 1.3V?
I know little about the electronics of this specific model. I think others can certainly step in. It is possible that the connecting wires of the FG coil have come loose or that a track on the board has been damaged. In that case, other Sony players will also start playing too fast. Or that the previous owner adjusted the playback speed while the motor was running too heavily, and that you now need to reduce the speed now that it is running smoothly again. In any case, it is important that no more slip occurs between the flywheel and the motor shaft.
