This thread will cover the parts necessary and the most common things that will need to be done on these walkmans to bring them in fully working order. I only have a handful of pictures for this tutorial. Will probably be updated in the future. Most people will sell these devices as in perfect working condition, despite there are some things that need to be fixed on all of them. PARTS NEEDED: https://fixyouraudio.com/product/sony-wm-dd10-walkman-repair-kit/
WHAT NEEDS TO BE DONE: 1. New rubber ring and new belt Belt is likely loose or has turned to goo. Rubber ring will probably have an indentation mark on it, if the device what not used for a long enough period of time. Unlike the rest of the DD range, these walkmans will require a different rubber ring (thinner and conical). It is important to use the thin ring, otherwise, you will need to adjust the thrust play to be very high (not recommended). 2. In some cases, motor spindle will need sanding, as it has old rubber/rust on it. For this, power the motor by a variable power supply at a voltage of 1.2-1.4V and keep an 800 grit piece of sandpaper on the spindle. After it becomes round you can finish it with a 2000 grit paper. After this, it's important to clean any sandpaper residue very well around the motor shaft. 3. Motor will need lubrication Use watch oil to lubricate both bearings of the motor. Be sure to clean the spindle of any residual oil. 4. Flywheel thrust play This should be checked to be within 0.1mm. If not, re-adjust it. 5. Motor position will need adjustment There is a left-right adjustment of the motor which needs to be adjusted so motor spindle is perfectly perpedincular to the flywheel. This adjustment has a significant impact on wow&flutter. It also needs to be done after the flywheel thrust play has been adjusted, as it's influenced by that adjustment. 6. Re-lubrication of mechanism is recommended There are some key points shown in one of the pictures below. Besides that, the motor and capstan bearing should also be lubricated. 7. Head may need to be straigtened to be parallel to the tape and azimuth adjusted 8. Capacitors will need replacement Usually not all of them will be leaky, but you should replace all for good measure. 9. Volume potentiometer needs cleaning Something like Kontakt 60 (what I use) or Deoxit will work the best. IPA can also be used. After you apply the solution of your choosing, it is important to rotate the pot about 10 full turns. 10. Adjust the tape speed with a 3kHz test tape. 11. Adjust the Dolby levels Using a 200nWb/m calibration tape, levels should be 100mV RMS at the Dolby measurement points on the back of PCB (measurement with no load). Note that only DD1 and DD10 have this adjustement, on DD11 and DD22 there is nothing to adjust. NOTE: If you are looking for a refurbished unit, ask for the rubber set (the ring is important, just a belt change is not enough) and for capacitors. These 2 are the absolute minimum that need to be done on these devices to be considered repaired. Many sellers do not give any specifics about the repair/resotoration, so just ask.
@JensMoba/BoomboxFan The series presented in this thread (DD1, DD10, DD11, DD22) do not have a center gear type mechanism, so that problem of a broken gear does not exist in this case. It is why I did not mention it in the steps or necessary parts. Even on the series with a center gear (WM-DD, WM-DDII, WM-DDIII, WM-DD30, WM-DD33, WM-DC2, WM-D3, WM-DD100), there is a new center gear available, so replacing the gear is the preffered solution in these cases.
Now I sell full repair kit on fixyouraudio,com site, including capacitors. It saves you time and money searching these parts.
