[Jukebox-list] mm-3 wiring

Joe Alberti jalberti at pacbell.net
Fri Jul 28 08:13:30 PDT 2000


Hi All.

Thanks for the responses.  :o)

I cleaned all the contacts for the selection system, and found one that was
horribly out of alignment.  It only made contact occasionally when the relay
fired.  I straightened and cleaned it and the selection problem seems to
have gone away. (Knock on wood).  The amplifier problem has gotten worse,
though.

The original stylus in the machine was pretty bad, so I didn't even try to
play any records with it.  I replaced it with a new one.  As far as the amp
goes, here is what I did before I powered it up:

The amp is totally solid state.  No tubes anywhere.  I unplugged the cables
from the amp and removed it from the jukebox.  On the reverse side, there
are three plug in boards similar to the kind that plug into a PC.  Two of
them are identical, and they are labeled as channel boards.  the third one
is a large board that contains the bass, treble, and balance controls.  I
removed all three boards from the amp chassis, and found that all of the
edge connectors were badly oxidized.  I cleaned all the edge connectors with
a pencil eraser, and they look good again.  I also cleaned the volume, bass,
treble, and balance controls.  I then looked everything over to see if
anything looked like it overheated or burned, and all looked good.

I then reassembled the amp and reinstalled it into the jukebox.  It sounded
pretty good and had good bass response for a few days, with the exception of
the left channel being weaker than the right channel.  I unplugged the
cartridge leads from the amp and reversed them, thinking that if the problem
was with the cartridge or the tone arm wiring, the problem would shift to
the other channel.  The problem stayed in the left channel.  I decided to
leave well enough alone for a while, and have continued to play the machine.
Now the bass response has begun to diminish.   I switched the channel boards
in the amp, and the problems remained.  The left channel is weak, and bass
is going bye bye.  I guess I'm gonna need to send this amp out for repair,
and was wondering if anyone knows of a reliable repair person who can fix a
Rowe/AMI solid state amp.

Thanks for all our help.

Joe


----- Original Message -----
From: Jens A. Hultgren <drjukebx at algonet.se>
To: <jukebox-list at lists.netlojix.com>
Sent: Tuesday, July 25, 2000 8:20 PM
Subject: Re: [Jukebox-list] mm-3 wiring


> One good feature (the best feature?) of stereo jukes is you can move
> tubes from one side to the other, and thus check if with which tube the
> problem also moves. However, capacitors are more likely to give trouble
> than tubes, and your amp may well be due for a rebuild.
> Jens
>
> James McClave wrote:
> >
> > joe, for your selection problem, sounds like the contacts need cleaned
> > on  your write-in assembly towards the lower right front of the
> > mechanism.they need to be real clean. use a good contact cleaner or very
> > very fine  emery paper. if that does not do it, check the alignment of
> > the little fingers, the alignment procedure is in the manual.  sound
> > problems- could need amp rebuild, its hard to guees on that. the loud
> > noise when cycling sounds like the mute switch may need cleaned and/ or
> > aligned properly to engage at the end of record, you mentioned that you
> > changed the needle,  how was the audio from the left side before you
> > changed the needle?  jim
> >
> > E-mail us at: trollmasters at webtv.net
> >
> > _______________________________________________
> > Jukebox-list mailing list
> > Jukebox-list at lists.netlojix.com
> > http://lists.netlojix.com/mailman/listinfo/jukebox-list
>
>
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