If anyone has a working Sony WM DD3 Quartz, could you post a picture of the wiring. Because I am restoring one, and it was working, it’s just the person who serviced it did a terrible job installing the center gear. But a few wires came off and I’m not sure I put them in the right place because there is no sound output. And no I’m not talking about the wires from the tape head. I just need to confirm because the service manual doesn’t really indicate it very well. I appreciate it.
It would be easier if you would post a picture with the wires that came off. Note the service manual does show where every wire goes on the PCB diagram (page 6 of the PDF).
Well, I soldered the wires where I thought they went based on pausing a YouTube video but even then I’m not a 100% Input everything back where it was supposed to, so I just want to corrrefrence. I dunno what Sony WM DDIII service manual you’re looking at though. The one from HiFi Engine does not show any form of wiring diagram.
This is the best picture I got it’s an absolute mess because who did the service before I did didn’t tape down the wires. So they were all over the place to begin with.
This is the manual I have: https://elektrotanya.com/sony_wm-dd3.pdf/download.html As a sidenote, don't need to quote previous posts. Just type in the box below post and use the "Post Reply" button instead of "Reply".
Sorry, every time I press reply to your comment it quotes it. Turns out, I wasn’t paying attention and you’re right, the diagram does show the wiring. But I don’t see anything that would contribute too the amplifier not working. Unless I’m not looking at it correctly. It seems like everything on the left side of the board has to do with motor and power functions. I just don’t know what could have happened.
Wait a minute. There are two leaf switches. At least I think that is on the left. Could that be the muting switch? Because the switch on the power side is off to the right.
There is only one leaf swich, muting is done by timing only on these units. Meaning the amps have a delay before they start. No muting in FF/REW. The secondary leaf is part of the DC in jack, which disconnects the battery when an AC adapter is plugged in to avoid accidentally "charging" the alkalines. Yes, from this view of the board, everything on the left is servo and PLL. What's the issue on your unit ?
Sorry, seen now you mentioned this in first post also. Do you have any noise (hiss) that varies with volume level or nothing at all on the output ? If nothing at all, chances are the amps are muted. Muting happens right after the volume pot. When powering up the device, Q302 briefly turns on until C305 charges. Muting time is given by R302-C305 time constant, which is exactly 1 second. First thing to check is the voltage at the bases of Q302, after the 1 second delay, both should be 0V.
Nothing at all. Could you tell me what pins I should probe? If it is the volume pot that I have a wm2 I could in theory swap it with. The only problem I see is that I began twiddling the post for the right and left channels and I don’t have an oscilloscope so I don’t know how I’m going to get the left and right channels back into balance.
The bases of Q302, as already stated. You will need at least a multimeter and some basic understanding of schematics (to make the correlations between schematic and PCB). Potentiometer isn't the main suspect here, but it cannnot be excluded either. Regarding imbalance, don't worry about that now. Focus on making the device work first, as for adjustment you will need a Dolby level tape anyway.
Okay what in your opinion pins I should look at on Q302. Because I’m looking at the pin layout and I’m trying to figure out what I should be probing.
