See my update. It was the dumb STK 4311 chip sets. I went through two replacement sets from ebay and the second set fixed it. I got the second set...
So it's finally repaired and back together. It was the two STK4311 amp chips. I replaced them with an ebay set early on and that didn't change...
I just checked the output of the bridge rectifier on both Panasonic and National and getting 24.5VDC with a quarter volt AC ripple.
After about eight months the highly recommended electronic repair specialist gave up and said troubleshooting this unit was too complicated. Of...
I was wondering about rail voltage too. I see what appears to be a full wave rectifier on the amp board and was getting ready to see what it's...
Good suggestion on the Japanese approach. I never heard of yahoo.jp. I just figured there was one internet and queries go everywhere. I will...
They are pretty cool. Not very portable, more like some hybrid of a small home stereo and boombox. I paid dearly for the Panasonic and then...
The great thing about this situation is that I own two of these and one is perfect. The way these systems are built is really nice; everything is...
It has to be simple. The only thing remotely complex are the two Sanyo STK4311 chips. I'm rusty and have no troubleshooting gear but a Fluke meter...
Looking for any tips on getting the distortion out of the amp. Nationals are a little different than the Panasonics. Service manual or amplifier...
Luggage that plays music.
More progress to the National. Availability of docs for these is scarce. I have the Panasonic version and the manual and I can say, having...
I added BT to everything lol. On most boom boxes there is a line in and thats what I attach the audio signals to on the back side of them. That...
I agree on being very cautious on lubricants. I've dissolved a couple vinyl based gears. The sturdier white plastics are robust but the amber...
The National is taking shape. When I bought it from South America, for parts only, it was missing: handle, metal straps, some slider knobs and...
I have a relatively nice Panasonic who was originally missing antenna and had a bad tape deck. I didn't much like the factory drivers so I...
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...
New here too. I can't guess at the model but looks like a JVC or Sanyo? Hopefully being in this group will get me investigating and learning more...
Greetings from Ohio, USA. My background is electronics via military and civilian occupations. I fell in love with boom boxes in the 80's when I...
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