Inversing the preamp chip on RX-5350

mmcodomino · Apr 14, 2016

Hi guys!

Brian and I are currently in the process of trying to fix a 5350 and it seems one channel of the preamp is deal. Can we just inverse the 3-pin IC to check if that is the solution?

Here is a data sheet of the chip:
http://www.weisd.com/store2/NTE373.pdf

Thanks a lot in advance!

TW5 · Apr 14, 2016

Doesn't look like a good idea at the moment
also need more info
Where is that part from ?

toshik · Apr 14, 2016

What are the symptoms? I've fixed them before.

mmcodomino · Apr 15, 2016

toshik said:
What are the symptoms? I've fixed them before.

Everything is working except for the left VU meter and the left channel when it is playing a tape.
Radio is strong on both channels and in stereo, so is line in. Just the left VU meter does not move to the music.

toshik · Apr 15, 2016

This is very typical issue. Does not need two of you to fix :-)

mmcodomino · Apr 15, 2016

toshik said:
This is very typical issue. Does not need two of you to fix

We already took the record bar apart and cleaned it. Same with the stereo/ambience switch.
Same symptoms.

What could be the cause of the problem?

toshik · Apr 15, 2016

Cleaning won't fix it

BoomboxLover48 · Apr 15, 2016

It is very common for the corner of the board on the left side to crack and and kill the left VU meter function. I had that issue with one of my 5350.

The second picture shows the crack. I used signal tracer and found the problem.

But no sound from the left channel and left VU meter not functioning could be related to signal loss due to another problem.

BoomboxLover48 · Apr 15, 2016

toshik said:
Cleaning won't fix it

Then what is your suggestion?

baddboybill · Apr 15, 2016

I would say check tape head and wiring for issues with left channel on deckðŸ¤”. Or function switch

Bad Boy Bill

jimmyjimmy19702010 · Apr 16, 2016

BoomboxLover48 said:
Then what is your suggestion?

he wants you to beg. :-)

BoomboxLover48 · Apr 16, 2016

jimmyjimmy19702010 said:
he wants you to beg.

BoomboxLover48 · Apr 16, 2016

toshik said:
This is very typical issue. Does not need two of you to fix

toshik said:
Cleaning won't fix it

We beg! Then how they can fix it?

mmcodomino · Apr 17, 2016

Thanks for your help so far. The board is not cracked anywhere. We just cleaned the function switch as well and are in the process of changing the belts right now which we might as well do while we are at it.
I'll let you know what it does once it is back together.

toshik · Apr 17, 2016

BoomboxLover48 said:
We beg! Then how they can fix it?

Your mailbox is full :-)

mmcodomino · Apr 17, 2016

No results. Same issues as before.

I got you message, toshik. Thanks! Where are you located? i don't feel like sending the board around would be a good idea though.

toshik · Apr 17, 2016

Location St. Augustine, FL

bredgeo · Apr 27, 2016

Hey all,

Thanks for the info and stuff!!!!

Toshik, I would love to sent the board... but you being in the US and the posties in Europe and America not always being nice, I don't wanna chance it!!!! :blush:

I think the chip we had a look at and changed might not be the preamp... I got the schematics, met up with a guy here that siad he will be able to look at her... I am gonna try that.

Later!

zzmbie · Aug 7, 2016

Hey to all,

i`m new here, but not in Boomboxes.

I have the same problem with the right channel, also only when tape is playing and only when the switch is on stereo. On ambience and mono both speakers working. :bang:

toshik · Aug 7, 2016

As I noted above it's a common problem

Inversing the preamp chip on RX-5350

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Attachments

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)

Member (SA)