Baffled by the 838 Biphonic

I got my JVC 838 today and it made the trip with no problems!

Ebay auction stated that it wouldn't power on so I took a chance because it looked to be in good shape.

Symptoms are on both AC and batteries.


Cassette will play (but slow)
Display will light when cassette is playing
I can get both meters to swing evenly by playing with the "mode" selection (mono, stereo, expand, biphonic)
Sound out of right speaker if I can get the mode switch just right but if I balance to the right there is no sound
Sound out of left speaker is no problem and is there 99% of the time.


Switch to radio, phono, or line in and the box does nothing
Out of all the functions, the least I was expecting to work was the cassette and it's the only part that does anything .

I know I will be opening this boombox up to clean, belts, and troubleshoot but do you guys have any idea where to start with the other functions not working? I worked the function switch a few times to see if it would make contact, but still only cassette works.....

Does the cassette normally play even if the power switch isn't to "on"? Maybe a bad power switch?

Any info is appreciated - thanks BoYz! (and holly)

Yes the cassette will play without turning on the power but when the cassette is playing, you should be able to switch to either the tuner or line in even if power switch is bad.

The rest of the issue -- clean first, then re-evaluate.

You are correct again Norm.

When I pull the cassette out (power switched off), hit play on the cassette deck with my MP3 hooked up via RCAs to the line in, I can switch to "line in" and hear the MP3 or switch to "radio" and I can tune all stations .



So, now what ?

Like Norm suggested, clean all the switches, especially the power switch, and then check again. The 838 is apparently prone to electrical contacts going bad, based on some previous posts. Hopefully it's nothing major.

had the same problem with one box -
took it to ramons -
he discovered that the box 'THOUGHT' it was in record mode --

so --it powered on like that -
and could play the tuner and line in -
while it was 'recording'

You guys are good - I have high hopes for this thing now .


So, I just need to make time to work on it . hahahaha

Thanks for the tips guys. It sounds like it will be the power switch or the cassette "record" switch........

blu_fuz said:

You guys are good - I have high hopes for this thing now .


So, I just need to make time to work on it . hahahaha

Thanks for the tips guys. It sounds like it will be the power switch or the cassette "record" switch........

Click to expand...

Ira was just pulling your leg Blu. Because EVERY boombox with a record feature, even those WITHOUT a line-in will monitor the line-in or Radio while recording.

Oh Ira you sneaky bastid!

Good luck with it, those 838's are nice for the right price

blu_fuz said:

Oh Ira you sneaky bastid!

Click to expand...

no -- serious -- ask ramon

if a box is stuck in record mode
---with or without a tape inside -

it will behave just like joes 838

--no tuner sound
no line in sound
power OFF wont work

but -- EVERYTHING works when a tape is in-
and its recording

Hmmm

On mine if I push FF/RW/or PLAY it will make the line in and radio work .

blu_fuz said:

Hmmm

On mine if I push FF/RW/or PLAY it will make the line in and radio work .

Click to expand...

This is the sleep mode, most bbx's have this. The purpose is to play a cassette and you can listen to any of the functions but when cassette stops the bbx turns off automatically This is why you should clean your power switch real good. It could also be a bad switch. I had to replace a couple switches that were bad. One I know was in my kingspoint

That makes perfect sense. I suspect a good cleaning and attention to the power switch will do the trick . You guys are great. Thank you.