Hi everyone, I bought a new WM-D3 from eBay (sold for spare parts but complete and in pretty good shape), changed centre gear, counter belt, etc... as per Marian's tutorial, and re-assembled everything back. I am now facing an issue where I get no sound at all when playing a cassette - be it from headphone or line out outputs. I don't even get static noise when tweaking the volume knob... Also tried to check input levels from line in, nothing comes through, leds won't light up. Any idea? I've visually checked the PCB and everything seems to be OK, no sign of leakage/corrosion... The only thing that I can see is some white sheen on some electronic components, but that's all (see pics) - as you can see I'm not an electronics-savvy guy, sorry for the lack of proper vocabulary. Thanks for any tips!
You forgot to mention if you had any sound before changing any parts. The "White sheen" on those brown condensers is normal . The playback/record switch is correctly engaged? Double check for any loose wires.
Thanks for your feedback! Problem is that I don't know as I didn't even tried to play it before changing the parts (lesson learned), was not expecting any electronic issue... No loose wires, playback/record switch correctly engaged. Still a conundrum for now, investigations ongoing.
Buying an item in this condition was always risky. But the seller did not say that the problem was only in the mechanics. At this point, it is best to work with the service manual and trace the signal path from the tape head through the preamp, Dolby amplifier, muting circuits, line amplifier/headphone amplifier, headphone amplifier muting. These are thick (bold) lines with arrows indicating the signal path for both stereo channels. This is a preview. Download the actual service manual.
Hi, i have the same problem with a D3 - no sound. it its hard to read and understand the circuit diagram for me - have to learn As suggested i start measuring - On IC 301 Pin1, 3, 15 i only have around 0.7V - have another Unit that work there are around 1.3 V Where i have to look now ? If head got enough voltage ? Many thanks for your time. Best Regards Tim
I would start with Vcc (pin 3 of IC301), which should be 2.25V with a 3V battery voltage. This voltage is generated by Q302 + internal circuit of TA7688 headphone amp. So a good start would be to measure voltage at emitter of Q302 (should be 3V) and take it from there. Note with NiMH cells voltages will be lower, 3V is considering alkaline batteries.
Thanks Valentine, i liftet a electrical tape and IC was corroded - i tried to clean and an resolder - but didnt worked. Please see my measures - i didnt understand whats going on. if base is 0.1 V how could emitter show 2.3V -or is it enough voltage ? in you opinion is the IC defective through corrosion ? many thanks for your help.
You got the pinout wrong, see picture attached. Pinout is pretty much standard on SOT-23 transistors. Q302 is added in this circuit to boost the output current of the ripple filter, but the IC can work without it for currents up to 10mA. Meaning that if you desolder just pin 11 of the IC from the board you should be getting 2.3V on that floating pin if the IC is good.
Many many thanks for your help and time. After lifting PIN11 - still nothing I replaced the IC from a F5 - and see another problem below the IC - Mute trace to PIN 5 was gone I repaired the trace and got a noise - and sometimes music The contact/switch close to the play button needs to cleaned and bent a bit to work properly. The D3 is back to live
Want to update this thread in regard to the solution. The no sound or intermittent sound is caused by corrosion on a flex cable underneath the battery tray. Seems to be a common problem on D3s that had battery leakeage, even if there's not necessarily very obvious signs in the compartment. Same problem is presented here at post #5: https://www.tapeheads.net/threads/sony-d3-walkman-no-sound.105170/ Solution is to remove the battery tray (it simply pulls, requies a bit of force) and repair the damaged flex cable as shown in attached pictures. Ideally add wire (0.25mm) to all traces, even if just some are open/high resistance. Then sand the tray to accomodate the extra thickness of the added wires/solder.
