Hi, I had been searching for information on my little HS-J02 Cassette Recorder and Player. I bought this superbe unit from new ages ago. Played it a bit but mostly it sat on my desk for years. About 15 years ago I tried to play it and of course the drive belt had melted! And no one supplied replacements, I thought it was scrap, but then a few years ago I heard of a place that specialised in belts and obtained one. Fitting was a nightmare but only made me more determined to fix it. It works now.....BUT on cassette playback the Right channel has a heavy hum that increases with turning the volume up. So it looks like the Volume pot is working but not getting a signal from the head. On FM radio both volume channels are fine. The head looks OK and really had little wear so I dont think its that. Can anyone suggest what it may be or how I can test it to locate the issue? I have good mechanical skills (I got the BELT in!!) but very rudimentary on the electrics. Assistance to get this working as intended would be much appreciated.
Welcome to the forum, the HS-J02 is one of my favorites but I'm not a repair expert. Try posting the question in the Walkman Tech Section, it will get more eyes on it. I always do the easy stuff first like DeOxit/Faderlube any moving switches and check the headphone jack for wear on the solder connections. (these are probably fine since it works with the radio). With boomboxes the function selector switch will cause a million problems when the player sits for years in one position. If yours sat with the switch on radio, it might need some contact cleaner on that switch (Power Off TAPE/Radio). I'm not sure which cleaner is good for these sliding switches, if I had to guess Faderlube? It depends on the type of contacts, DeOxit like metal only. Otherwise it might need new parts like capacitors and that gets beyond my troubleshooting.
Just on the surface it sounds like a broken wire from the tape head to the pre-amp. At least, in my experience that's a good place to start especially after replacing belts or disassembly. If auto reverse, see if hum is in both directions.
