Toyota radio/cassette question

[R3Jar]

Does anybody know how a combination radio/cassette player senses the end of
tape? I have a radio/cassette player in my Toyota Previa Van that started to
periodically eject the tape or reverse itself. I dealt with it and it continued
to work intermittently until now when I insert a tape it plays for about a half
of a second and then ejects. I thought it might sense drag on the tape but that
cannot be the cause. Can somebody tell me what to look for or how to repair
this? This maybe an electronic problem as now I notice that if I try to insert
a tape and press the fast forward or reverse buttons the radio goes to radio
mode???? If I knew how it sensed the end of tape or what it senses to reverse
and play I could repair it. I have removed the player from the vehicle and also
the cassette mechanism and noticed a belt on the underside. Replace that belt
with one very similar with no change of symtoms. Maybe bad motor? The radio is
in a Toyota Previa Van. It has a 11709 number on it but no other distinguishing
manufacturers numbers.
Hope that
somebody knows something.
Thanks in advance

 

[Jerry G.]

I cannot say for your particular model, but I can give a general idea.

The higher end of the cassette units will sense the leader on the tape,
using an IR LED and sensor. The lower end units will do it by torque
measurement, using reel velocity sensing. For safety, they all use some
type of reel velocity sensing, so that if the IR sensing fails, the
motors won't keep pulling the reels forever, or until something burns
out or becomes damaged.

In the case of auto units, make sure that everything inside is clean,
and all mechanical pieces are moving properly to start with.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"R3Jar" <r3jar@aol.com> wrote in message
news:20030816121731.00695.00000065@mb-m02.aol.com...
Does anybody know how a combination radio/cassette player senses the end
of
tape? I have a radio/cassette player in my Toyota Previa Van that
started to
periodically eject the tape or reverse itself. I dealt with it and it
continued
to work intermittently until now when I insert a tape it plays for about
a half
of a second and then ejects. I thought it might sense drag on the tape
but that
cannot be the cause. Can somebody tell me what to look for or how to
repair
this? This maybe an electronic problem as now I notice that if I try to
insert
a tape and press the fast forward or reverse buttons the radio goes to
radio
mode???? If I knew how it sensed the end of tape or what it senses to
reverse
and play I could repair it. I have removed the player from the vehicle
and also
the cassette mechanism and noticed a belt on the underside. Replace that
belt
with one very similar with no change of symtoms. Maybe bad motor? The
radio is
in a Toyota Previa Van. It has a 11709 number on it but no other
distinguishing
manufacturers numbers.
Hope that
somebody knows something.
Thanks in advance

 

[Steve Reinis]

This doesn't answer your question about the problems you are having, but it
does clarify one bit...

How old is this Previa? I have a 1991 4Runner, and also a 1990 Cressida
with very similar factory stereo systems. Both have cassette decks, but the
4Runner has the double-DIN unit with a CD player, too. Anyhow, both have a
rather nice feature of switching over to the tuner when you are fast winding
a tape in either direction. The owner's manual describes how to turn this
feature on and off.

My unit in the 4Runner was made by Matsuhita (Panasonic). The unit in the
Cressida has no labels... Interesting.

-Steve


R3Jar <r3jar@aol.com> wrote in message
news:20030816121731.00695.00000065@mb-m02.aol.com...

Does anybody know how a combination radio/cassette player senses the end
of
tape? I have a radio/cassette player in my Toyota Previa Van that started
to
periodically eject the tape or reverse itself. I dealt with it and it
continued
to work intermittently until now when I insert a tape it plays for about a
half
of a second and then ejects. I thought it might sense drag on the tape but
that
cannot be the cause. Can somebody tell me what to look for or how to
repair
this? This maybe an electronic problem as now I notice that if I try to
insert
a tape and press the fast forward or reverse buttons the radio goes to
radio
mode???? If I knew how it sensed the end of tape or what it senses to
reverse
and play I could repair it. I have removed the player from the vehicle and
also
the cassette mechanism and noticed a belt on the underside. Replace that
belt
with one very similar with no change of symtoms. Maybe bad motor? The
radio is
in a Toyota Previa Van. It has a 11709 number on it but no other
distinguishing
manufacturers numbers.
Hope that
somebody knows something.
Thanks in advance

 

[Asimov]

"Jerry G." bravely wrote to "All" (17 Aug 03 00:07:27)
--- on the topic of "Re: Toyota radio/cassette question"

Jerry, sometimes a little tape tension lever which connects to a switch
and/or also keeps track of the reel counter activity for the autostop.

What might be happening to the Previa owner is that the cassette tape is
warped or damaged and the drag is triggering the autostop mechanism.
There may be nothing wrong with the player...

JG> From: "Jerry G." <jerryg@total.net>

JG> I cannot say for your particular model, but I can give a general idea.

JG> The higher end of the cassette units will sense the leader on the
JG> tape, using an IR LED and sensor. The lower end units will do it by
JG> torque measurement, using reel velocity sensing. For safety, they all
JG> use some type of reel velocity sensing, so that if the IR sensing
JG> fails, the motors won't keep pulling the reels forever, or until
JG> something burns out or becomes damaged.

JG> In the case of auto units, make sure that everything inside is clean,
JG> and all mechanical pieces are moving properly to start with.

JG> --

JG> "R3Jar" <r3jar@aol.com> wrote in message
JG> news:20030816121731.00695.00000065@mb-m02.aol.com...
JG> Does anybody know how a combination radio/cassette player senses the
JG> end of
JG> tape? I have a radio/cassette player in my Toyota Previa Van that
JG> started to
JG> periodically eject the tape or reverse itself. I dealt with it and it
JG> continued
JG> to work intermittently until now when I insert a tape it plays for
JG> about a half
JG> of a second and then ejects.

.... KPLA: Klingon Radio: All Klingon Opera, All The Time.

 

[matt morian]

r3jar@aol.com (R3Jar) wrote in message news:<20030816121731.00695.00000065@mb-m02.aol.com>...

Does anybody know how a combination radio/cassette player senses the end of
tape? I have a radio/cassette player in my Toyota Previa Van that started to
periodically eject the tape or reverse itself. I dealt with it and it continued
to work intermittently until now when I insert a tape it plays for about a half
of a second and then ejects. I thought it might sense drag on the tape but that
cannot be the cause. Can somebody tell me what to look for or how to repair
this? This maybe an electronic problem as now I notice that if I try to insert
a tape and press the fast forward or reverse buttons the radio goes to radio
mode???? If I knew how it sensed the end of tape or what it senses to reverse
and play I could repair it. I have removed the player from the vehicle and also
the cassette mechanism and noticed a belt on the underside. Replace that belt
with one very similar with no change of symtoms. Maybe bad motor? The radio is
in a Toyota Previa Van. It has a 11709 number on it but no other distinguishing
manufacturers numbers.
Hope that
somebody knows something.
Thanks in advance

If your mechanically inclined at all, take it out, take the cover off.
It sounds like the tension wheels are dirty and causing the drag. Take
some Q-tips and a little rubbing alcohol and clean the wheels. If you
can supply power to it, stick a tape in and you can how it all works
and what may be wrong. This may be a little to much for you if your
not a tinker'er. Now days you can get a high end tape deck for under
$100.

-Matt

 

[Jeff]

"matt morian" <mpm_three@yahoo.com> wrote in message
news:da2e7b9c.0308171111.10ec7942@posting.google.com...

r3jar@aol.com (R3Jar) wrote in message
news:<20030816121731.00695.00000065@mb-m02.aol.com>...
Does anybody know how a combination radio/cassette player senses the end
of
tape? I have a radio/cassette player in my Toyota Previa Van that
started to
periodically eject the tape or reverse itself. I dealt with it and it
continued
to work intermittently until now when I insert a tape it plays for about
a half
of a second and then ejects. I thought it might sense drag on the tape
but that
cannot be the cause. Can somebody tell me what to look for or how to
repair
this? This maybe an electronic problem as now I notice that if I try to
insert
a tape and press the fast forward or reverse buttons the radio goes to
radio
mode???? If I knew how it sensed the end of tape or what it senses to
reverse
and play I could repair it. I have removed the player from the vehicle
and also
the cassette mechanism and noticed a belt on the underside. Replace that
belt
with one very similar with no change of symtoms. Maybe bad motor? The
radio is
in a Toyota Previa Van. It has a 11709 number on it but no other
distinguishing
manufacturers numbers.
Hope that
somebody knows something.
Thanks in advance

If your mechanically inclined at all, take it out, take the cover off.
It sounds like the tension wheels are dirty and causing the drag. Take
some Q-tips and a little rubbing alcohol and clean the wheels. If you
can supply power to it, stick a tape in and you can how it all works
and what may be wrong. This may be a little to much for you if your
not a tinker'er. Now days you can get a high end tape deck for under
$100.

-Matt

You could not get one built half as good as that one
for 3 times as much.
Jeff