Hi everyone, On to my next project. A Sony Walkman WM-D3 that I won in a local auction along with a D6C. Both in mint condition externally! Anyway starting with the D3 that has zero electrical function (with batteries) and a FF button that will not press down. The play, rewind, and stop buttons all seem to have normal travel and engagement. Decided to tackle the mechanical issue first. I Removed the covers and can see under the FF button is a stainless plate. The plate does not budge when press down on the button. The rewind button has clearance under it and so travels down freely. So my first of many questions with this repair/restoration is, is that stainless plate not supposed to be there normally, or is that plate supposed to be there but move down when FF button is pushed? This will be a longish journey as I both need to replace the cracked center gear as well as resolve the no power issue. Any advice or wisdom greatly appreciated! Mark
Hi everyone, So after reviewing Marians center gear repair instructions I see the plate I’m talking about IS the center gear assembly. I also found the video of Marian testing a prototype and I can clearly see the plate(s) move up and down with the FF and REW buttons. Looks like I’m in for full disassembly right out of the gate. Before I buy Marians center gear I guess now I need to determine why no motion of the motor. If it is the commonly failed servo control chip or whatever it is, I need to figure out if the D3 has one of the impossible to find ones. If it is, looks like I will be at a standstill. I can’t find any videos online of anyone replacing the center gear in a D3. Because of the record feature there must be some extra parts Does anyone know if the center gear from the D3 has a how to video for gear replacement? My components all look different from what I see in Marians instructions and other videos. As always, thank you in advance for any thoughts or advice. Mark
The servo IC was used in more Walkman units. I have logged these so far, there most like are more units that I did not look into yet on WML:
@Dauner There's nothing signficantly different on the WM-D3 as far as replacing the center gear. Only thing extra you need to remove in the REC lever, hence why I don't think a separate tutorial specifically for the D3 is needed. I suggest going through the tutorial a couple of times and understand all the steps before attempting to do the repair. You say you have no power to the motor, but does the unit works otherwise ? - battery check LEDs; - amplifier noise (hiss) in the headphones that varies with volume; In regard to the CX20084, check if you have 1.5V on pin 5.
Thanks Valentin, I will read the final version of the tutorial a couple of times again. I have the record levers removed (easy to do, and I have a lot of pictures), and so if have any questions I’ll post here. When I removed the lower arm I found a black plastic washer “floating” on a nearby component, but I believe it is part number 3-701-436-11 “WASHER, 1.6” item number 114 in the Service Manual. Sits on top of a spring. For power I was looking at things late last night and realized I have power with batteries installed but not with 3V jack. I both get increasingly louder hiss with volume pot as well as battery meter working with Play depressed. I’ll check voltage on the CX20084 pin 5. Thanks again, Mark
Hi Valentin, Checked voltages on CX20084. Pin 5 was 0V. Pin 8 was 3V. Pin 15 was 2.4V. Others were zero or slightly negative. It looks like I’m a couple of years late in finding a replacement chip. Very unfortunate. I guess I’m on hold for now. Thanks again, Mark
There is a lengthy, recent thread about the IC: https://stereo2go.com/forums/threads/chasing-the-sony-cx20084-speed-chip-for-d6c-walkman.7794/
Quick pic of the Servo chip. Looks pretty crusty along the one side. I checked capacitance of C606 with my fluke 117 and it shows 50uF. Not shorted but way out of spec. There’s another cap C315 that is same spec and it reads 12uF which I’d say is OK.
@Dauner : start searching for bad looking units with the IC. Chances are slim to pick up a just real IC from online sources.
I would try removing C606 and measuring it out of circuit. If it still out of spec then try replacing it and cleaning the contamination off the IC and its pins. It is an outside chance but worth trying before buying another chip.
Thanks Emiel. I have restored a number of Sony and Aiwa walkmans, and so I think it's a good idea to start searching for these chips for current and future needs. Deb64, Probably a good idea. I'll remove it and see what it reads then. Somewhat related: Can you all tell me what is going on with Pin 9? I'm not an electrical engineer, but I don't recall ever seeing a component direct soldered to an IC pin. Are all of the DD walkmans like this? Thanks again, Mark
Hi quick follow-up on the mechanical side of things. As it turns out, even with all of the requisite parts removed, I still can’t budge the center gear assembly either up or down. I had assumed there was something lodged underneath that was preventing it from moving down on the shaft where the large brass bushing is, but it actually won’t move up either. Has anyone who has done DD disassembly ever seen this before? Maybe SUPER dried grease? I drizzled a drop of WD40 there and will let soak overnight. I know the reed switch is still there but that’s not limiting anything. Thanks! Mark
Just closing the loop in case anyone else is ever in a similar situation. I opted to use force and try prying the center gear assembly off the stuck shaft. It took quite a bit (much more than my better judgement would have advised) but I was able to pry things free. It was stiff the entire way off. I cleaned the brass bore and its mating shaft with IPA and it now travels smoothly. mark
