Problems with a Pioneer CT-F1250 cassette deck

Archived from groups: sci.electronics.repair,rec.audio.tech (More info?)

Hello all,
I recently rescued an old and beautiful Pioneer CT-F1250 cassette
deck from a friend's trash heap! It was in great shape but
appears to need some work to bring it back up to spec again.
Most seriously, there is a large power resistor (7W, 12ohms) on
a vertical board that overheats (to the point of smoking!). I believe
this may be related to the quartz lock circuitry, because it only
happens during playback and record, and the circuit board has
one section that is labelled "pulse count". The second
issue that it seems to have is that the tape calibration doesn't
seem very stable -- the ideal setting for each knob
(bias/level/eq) seems to fluctuate over time, even over the course
of a calibration run.

Can anyone offer any hints and tips in troublehsooting and repairing
one of these grand decks? Or possibly someone willing to share a copy of
the service manual? It is in fantastic shape and I'd hate to
see it go to waste!

Thanks in advance,
Mike

Archived from groups: sci.electronics.repair,rec.audio.tech (More info?)

Except if it's really shorted, the resistor mentioned is toast long before
the motor gets hot. One could just disconnect the motor and see if the
resistor stops heating up.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Nigel" <Nigel@nospam.com> wrote in message
news:7n7Ec.5350$NA1.489618@news02.tsnz.net...
> leemichaelb@yahoo.com (Mike Lee) wrote in
> news5386fa.0406281006.2e89ad1e@posting.google.com:
>
> > Hello all,
> > I recently rescued an old and beautiful Pioneer CT-F1250 cassette
> > deck from a friend's trash heap! It was in great shape but
> > appears to need some work to bring it back up to spec again.
> > Most seriously, there is a large power resistor (7W, 12ohms) on
> > a vertical board that overheats (to the point of smoking!). I believe
> > this may be related to the quartz lock circuitry, because it only
> > happens during playback and record, and the circuit board has
> > one section that is labelled "pulse count". The second
> > issue that it seems to have is that the tape calibration doesn't
> > seem very stable -- the ideal setting for each knob
> > (bias/level/eq) seems to fluctuate over time, even over the course
> > of a calibration run.
> >
> > Can anyone offer any hints and tips in troublehsooting and repairing
> > one of these grand decks? Or possibly someone willing to share a copy
of
> > the service manual? It is in fantastic shape and I'd hate to
> > see it go to waste!
> >
> > Thanks in advance,
> > Mike
> >
>
>
> Have you checked the motor ? If it's faulty and drawing heaps of current,
> you should be able to feel it getting warm.
>
>
>
>
> --
> http://www.ratestogo.com/guest.asp?id=746183

Archived from groups: sci.electronics.repair,rec.audio.tech (More info?)

Thanks both of you for the feedback. I will try disconnecting the
motor and
seeing what happens. Strangely, though, I'm fairly certain that the
resistor
heats up only during playback and record ... and since the capstans
are always turning, and the hubs turn for all transport modes
including FF and RW, it doesn't seem likely that the motor would be at
fault. But I will try it anyway, and post back here with the
results...

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message news:<2kcshmFpnvvU1@uni-berlin.de>...
> Except if it's really shorted, the resistor mentioned is toast long before
> the motor gets hot. One could just disconnect the motor and see if the
> resistor stops heating up.
>
> Mark Z.
>
> --
> Please reply only to Group. I regret this is necessary. Viruses and spam
> have rendered my regular e-mail address useless.
>
>
> "Nigel" <Nigel@nospam.com> wrote in message
> news:7n7Ec.5350$NA1.489618@news02.tsnz.net...
> > leemichaelb@yahoo.com (Mike Lee) wrote in
> > news5386fa.0406281006.2e89ad1e@posting.google.com:
> >
> > > Hello all,
> > > I recently rescued an old and beautiful Pioneer CT-F1250 cassette
> > > deck from a friend's trash heap! It was in great shape but
> > > appears to need some work to bring it back up to spec again.
> > > Most seriously, there is a large power resistor (7W, 12ohms) on
> > > a vertical board that overheats (to the point of smoking!). I believe
> > > this may be related to the quartz lock circuitry, because it only
> > > happens during playback and record, and the circuit board has
> > > one section that is labelled "pulse count". The second
> > > issue that it seems to have is that the tape calibration doesn't
> > > seem very stable -- the ideal setting for each knob
> > > (bias/level/eq) seems to fluctuate over time, even over the course
> > > of a calibration run.
> > >
> > > Can anyone offer any hints and tips in troublehsooting and repairing
> > > one of these grand decks? Or possibly someone willing to share a copy
> of
> > > the service manual? It is in fantastic shape and I'd hate to
> > > see it go to waste!
> > >
> > > Thanks in advance,
> > > Mike
> > >
> >
> >
> > Have you checked the motor ? If it's faulty and drawing heaps of current,
> > you should be able to feel it getting warm.
> >
> >
> >
> >
> > --
> > http://www.ratestogo.com/guest.asp?id=746183

Archived from groups: sci.electronics.repair,rec.audio.tech (More info?)

In article <1cfa6663.0407010140.7c602770@posting.google.com>,
<reverend_rogers@yahoo.com> wrote:

> Silver pioneer website? sounds like I need to take a look there!
> Could you possibly post the URL?
> cheers, Ben

http://www.silverpioneer.com. They are in the process of moving,
so it might be http://silverpioneer.netfirms.com by the time you
see this posting. I also have my silver collection displayed on
my website, http://www.johnweeks.com/stuff/pioneer.

-john-

--
====================================================================
John A. Weeks III 952-432-2708 john@johnweeks.com
Newave Communications http://www.johnweeks.com
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