I’m trying to get a Walkman sports (WM-F63) functioning again. Radio and tape transport work ok, but with tape the only sound is a loud buzz whenever the tape is moving, i.e. on play, fast forward, and rewind. Seems to vary a little when I press on the cassette. What might cause this and is it an easy fix?
I have multiple WM-F63 all have the same issues. I used to buy this model to have one in working condition. After buying several of them I gave up. None of them work, All have exactly the same problem. This problem is not because of a disconnected wire. There must be a weak electronic part related to audio.
The service manual and schematics are available from Elektrotanya so you could measure the voltages at pre amp IC301 and Dolby chip IC302. From here the audio passes to IC501 headphone amp but given the tuner work ok I'd check the other ICs first.
Do you have a digital multimeter that can read voltage, continuity and resistance? If yes then you can start by measuring the voltage at the different parts of the circuit board according to the schematic. I can help if you want to learn. You can get a pocket multimeter from eBay for less than £10. You don't really need expensive equipment for debugging faults on walkmans.
Then as shown in the diagram ... the green wires are the audio output of the radio .... the red arrows are the audio output of the cassette ... if the audio of the radio is ok I would try like this ... disconnect capacitor C 207 or 107 for the other channel and then I would try to connect a capacitor as in the picture ... if doing so or the audio of the cassette even at low volume would make me understand that the problem is on the cip of the dolby nr if instead I still had no audio ... the problem is on the cip pre amp ....
I would love to learn and I very much appreciate your help. I do have digital multimeter but as I said I don't know how to convert the real circuit board to the one shows on the service manual to check it.
I agree with Silver965, if you have multiple WM-F63 with the same issue it does point towards failing electrolytic capacitors. Rather than checking the circuit voltages it makes more sense to simply replace the capacitors. You need to replace with the same capacitance value and same or higher voltage rating. This info will be printed on the side of the capacitor. The service manual has drawings of both the schematic diagram and the placement drawing (location of each component). The electrolytic capacitors are usually polarised, so make sure the leg marked " - " (negative) is fitted the correct way round. I always take a lot of photos while working to make sure I know where everything goes. Use a fine tip soldering iron, solder wick (braid) to remove excess solder and flux helps the solder to flow nicely. Clean excess flux with flux remover or alcohol, I use an old toothbrush to scrub the flux off.
