Science and Technology news... :: View topic - HELP - Please Identify These Two Parts....................

EADGBE · Guest

I have a "rainy afternoon project" that has got me puzzled.

I have an old Pioneer cassette deck that I am restoring.

The capstan motor worked for a short while, then it stopped.

The casing of the motor felt VERY warm, so I knew something was
amiss.

(One of the voltage regulators in the deck>s main power supply became
EXTREMELY hot whenever the capstan motor was connected, which was
another clue).

Suspecting a short in the capstan motor, I took the motor apart.

Take a look at what I found when I examined the motor>s internal
voltage regulator circuit board...

http://i240.photobucket.com/albums/ff58/eadgbe123/SCORCHED.jpg

The motor>s voltage regulator had burned itself up. Look at how
scorched the circuit board is!

I have a replacement regulator, but I want to make sure that all is
well inside this circuit before installing the replacement. (Yes, I
KNOW that I could simply get another motor, but remember, I am
tinkering for the sake of tinkering!)

So I have been checking all of the other components in this circuit,
to verify their health.

The one component that has me puzzled is the small black "diode"
indicated at the bottom of the photo.

There is no mark on this component other than the yellow stripe you
see.

I cannot get any type of reading on this component when I use my
multimeter -- I get nothing using my diode check function (forward or
reverse bias), no continuity, no resistance reading. It must be
faulty, I am assuming.

The other component that has me puzzled is the olive green "resistor"
just above the larger blue electrolytic capacitor. I get a steady
resistance reading of .5 ohms on this component.

I am going to disconnect at least one leg of each of these two
"mystery components" and take further readings, but I>m not used to
getting such odd readings right off the bat on these two components.

Can anyone provide any clues as to what these components are?

BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with
no AC voltage ripple present. I have verified this.

Thanks In Advance.....

Reinhard Zwirner · Guest

EADGBE schrieb:
[quote]
Actually, I>ll do just a bit better.

Here are ALL of the circuit board traces, done as best as I can. Let
me know if the traces aren>t clear enough:

http://i240.photobucket.com/albums/ff58/eadgbe123/CIRCUIT.jpg

By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.
[/quote]
Obviously, you>ve forgotten the red connection:

<http://www.bilder-hochladen.net/files/12b4-2t-jpg.html>

HTH

Reinhard

N_Cook · Guest

EADGBE <hwbosshoss@comcast.net> wrote in message
news:1d54ff05-d190-402a-aebb-6e9e51de736c@j22g2000hsf.googlegroups.com...
[quote]
I have a "rainy afternoon project" that has got me puzzled.

I have an old Pioneer cassette deck that I am restoring.

The capstan motor worked for a short while, then it stopped.

The casing of the motor felt VERY warm, so I knew something was
amiss.

(One of the voltage regulators in the deck>s main power supply became
EXTREMELY hot whenever the capstan motor was connected, which was
another clue).

Suspecting a short in the capstan motor, I took the motor apart.

Take a look at what I found when I examined the motor>s internal
voltage regulator circuit board...

http://i240.photobucket.com/albums/ff58/eadgbe123/SCORCHED.jpg

The motor>s voltage regulator had burned itself up. Look at how
scorched the circuit board is!

I have a replacement regulator, but I want to make sure that all is
well inside this circuit before installing the replacement. (Yes, I
KNOW that I could simply get another motor, but remember, I am
tinkering for the sake of tinkering!)

So I have been checking all of the other components in this circuit,
to verify their health.

The one component that has me puzzled is the small black "diode"
indicated at the bottom of the photo.

There is no mark on this component other than the yellow stripe you
see.

I cannot get any type of reading on this component when I use my
multimeter -- I get nothing using my diode check function (forward or
reverse bias), no continuity, no resistance reading. It must be
faulty, I am assuming.

The other component that has me puzzled is the olive green "resistor"
just above the larger blue electrolytic capacitor. I get a steady
resistance reading of .5 ohms on this component.

I am going to disconnect at least one leg of each of these two
"mystery components" and take further readings, but I>m not used to
getting such odd readings right off the bat on these two components.

Can anyone provide any clues as to what these components are?

BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with
no AC voltage ripple present. I have verified this.

Thanks In Advance.....
[/quote]
Is the diode oriented to soak up back emfs from the motor ?
The green thing is an inductor

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

EADGBE · Guest

The anode of the diode is attached directly to three of the resistors
as shown.

I have tried to re-create the circuit board traces on the other side.

The cathode connects to what N_Cook has described as an inductor.

Take a look at this photo:

http://i240.photobucket.com/albums/ff58/eadgbe123/DIODE.jpg

Thanks to everyone for your help so far.

Any chance of finding a replacement for this diode?

EADGBE · Guest

Actually, I>ll do just a bit better.

Here are ALL of the circuit board traces, done as best as I can. Let
me know if the traces aren>t clear enough:

http://i240.photobucket.com/albums/ff58/eadgbe123/CIRCUIT.jpg

By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.

Jamie · Guest

EADGBE wrote:

[quote]I have a "rainy afternoon project" that has got me puzzled.

I have an old Pioneer cassette deck that I am restoring.

The capstan motor worked for a short while, then it stopped.

The casing of the motor felt VERY warm, so I knew something was
amiss.

(One of the voltage regulators in the deck>s main power supply became
EXTREMELY hot whenever the capstan motor was connected, which was
another clue).

Suspecting a short in the capstan motor, I took the motor apart.

Take a look at what I found when I examined the motor>s internal
voltage regulator circuit board...

http://i240.photobucket.com/albums/ff58/eadgbe123/SCORCHED.jpg

The motor>s voltage regulator had burned itself up. Look at how
scorched the circuit board is!

I have a replacement regulator, but I want to make sure that all is
well inside this circuit before installing the replacement. (Yes, I
KNOW that I could simply get another motor, but remember, I am
tinkering for the sake of tinkering!)

So I have been checking all of the other components in this circuit,
to verify their health.

The one component that has me puzzled is the small black "diode"
indicated at the bottom of the photo.

There is no mark on this component other than the yellow stripe you
see.

I cannot get any type of reading on this component when I use my
multimeter -- I get nothing using my diode check function (forward or
reverse bias), no continuity, no resistance reading. It must be
faulty, I am assuming.

The other component that has me puzzled is the olive green "resistor"
just above the larger blue electrolytic capacitor. I get a steady
resistance reading of .5 ohms on this component.

I am going to disconnect at least one leg of each of these two
"mystery components" and take further readings, but I>m not used to
getting such odd readings right off the bat on these two components.

Can anyone provide any clues as to what these components are?

BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with
no AC voltage ripple present. I have verified this.

Thanks In Advance.....
Well, I guess you now know why the reg burt up.[/quote]
that diode is suppose to go across the motor leads to suppress back
EMF which can damage components..
It would be a simply low current SI diode.

http://webpages.charter.net/jamie_5"

EADGBE · Guest

OK, here is the circuit again, this time with positive and negative
power inputs labeled....

http://i240.photobucket.com/albums/ff58/eadgbe123/CIRCUIT_2.jpg

EADGBE · Guest

I should point something out that I haven>t mentioned before...

There are two slots in the circuit board.

One of them is just above the smaller black electrolytic capacitor,
and the other slot is just below the larger blue electrolytic
capacitor.

You can see the traces going to these slots and appearing to "stop
dead".

These slots are where the motor contacts are soldered.

PeterD · Guest

On Sun, 5 Oct 2008 17:48:53 -0700 (PDT), EADGBE
<hwbosshoss@comcast.net> wrote:

[quote]Actually, I>ll do just a bit better.

Here are ALL of the circuit board traces, done as best as I can. Let
me know if the traces aren>t clear enough:

http://i240.photobucket.com/albums/ff58/eadgbe123/CIRCUIT.jpg

By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.
[/quote]
WHere does the motor winding itself attach? I>m guessing that the pins
on the 'bottom' of the image are teh power input, right?

Kevin McMurtrie · Guest

In article <e-edna_3HJZn4HTVnZ2dnUVZ_jWdnZ2d@posted.pcez>,
"Richard Crowley" <rcrowley@xp7rt.net> wrote:

[quote]"EADGBE" wrote ...
The anode of the diode is attached directly to three of the resistors
as shown.

I have tried to re-create the circuit board traces on the other side.

The cathode connects to what N_Cook has described as an inductor.

Take a look at this photo:

http://i240.photobucket.com/albums/ff58/eadgbe123/DIODE.jpg

Thanks to everyone for your help so far.

Any chance of finding a replacement for this diode?

Depending on what the actual diagram looks like,
it is quite possibly a simple, generic silicon diode
like a 1N4001 (power rectifier) or maybe even a
popular signal diode like a 1N4148, etc. These
are both very common parts that likely cost only
a few cents in production quantities.
[/quote]
I believe it takes at least two transistors. It>s a positive feedback
system to compensate for losses in the motor, creating a virtual perfect
motor that doesn>t change speeds under load. And that brings about the
second problem...

The circuit has only one pot so it>s not going to work on a worn motor.
The loss compensation is a fixed resistor so it>s only good for a motor
in perfect condition.

--
Google is a pro-spamming service. I will not see your reply if you use Google.

Richard Crowley · Guest

"Franc Zabkar" wrote ...
[quote]"Richard Crowley" composed:
"Franc Zabkar" wrote ...
EADGBE composed:
By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.

My vrt databook lists the TDA1151 and TDA1152 as equivalents for the
AN6610.

Which themselves are listed as "obsolete, discontinued, or hard-to-find".
IMHO, doesn>t seem worth the effort for an 87-cent motor. YMMV

I can buy the AN6610 here in Australia for AU$2.75.
[/quote]
OK, then that would mean paying AU$2.75 to repair a motor
that likely isn>t worth half that. Not to mention that without
knowing why the original blew, the OP has an excellent chance
of blowing up the replacement instantly. That doesn>t make
sense up here in the Northern Hemisphere. Perhaps things
look different from your perspective. :-)

Franc Zabkar · Guest

On Sun, 5 Oct 2008 20:56:11 -0700, "Richard Crowley"
<rcrowley@xp7rt.net> put finger to keyboard and composed:

[quote]"Franc Zabkar" wrote ...
EADGBE composed:
By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.

My vrt databook lists the TDA1151 and TDA1152 as equivalents for the
AN6610.

Which themselves are listed as "obsolete, discontinued, or hard-to-find".
IMHO, doesn>t seem worth the effort for an 87-cent motor. YMMV
[/quote]
I can buy the AN6610 here in Australia for AU$2.75.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Richard Crowley · Guest

"EADGBE" wrote...
[quote]I should point something out that I haven>t mentioned before...
There are two slots in the circuit board.

One of them is just above the smaller black electrolytic capacitor,
and the other slot is just below the larger blue electrolytic
capacitor.

You can see the traces going to these slots and appearing to "stop
dead".

These slots are where the motor contacts are soldered.
[/quote]
Then it appears that you didn>t trace the circuit properly.

According to your green lines, the only path from the
upper motor node is through the adjustable resistor
at the top (highly unlikely for such a high impedance
as 5000 ohms) or through the black electrolytic
capacitor (electrically impossible).

How about just posting a photo of the BACK of the
board instead of trying to interpret it?

There IS a direct path from the +power input to the
lower motor node, which seems consistent with the
motor speed regulator IC circuit.

Did you say that you *have* a replacement for the
semiconductor in hand, or that you had simply
identified it?

Richard Crowley · Guest

"Franc Zabkar" wrote ...
[quote]EADGBE composed:
By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.

My vrt databook lists the TDA1151 and TDA1152 as equivalents for the
AN6610.
[/quote]
Which themselves are listed as "obsolete, discontinued, or hard-to-find".
IMHO, doesn>t seem worth the effort for an 87-cent motor. YMMV

Franc Zabkar · Guest

On Sun, 5 Oct 2008 17:48:53 -0700 (PDT), EADGBE
<hwbosshoss@comcast.net> put finger to keyboard and composed:

[quote]Actually, I>ll do just a bit better.

Here are ALL of the circuit board traces, done as best as I can. Let
me know if the traces aren>t clear enough:

http://i240.photobucket.com/albums/ff58/eadgbe123/CIRCUIT.jpg

By the way, the AN6601 laid flat against the circuit board, with the
label side DOWN.
[/quote]
My vrt databook lists the TDA1151 and TDA1152 as equivalents for the
AN6610.

Here is a datasheet and application circuits for the TDA1151:
http://www.datasheetarchive.com/pdf-datasheets/Datasheets-32/DSA-633666.pdf

This is an equivalent NTE part:
http://www.nteinc.com/specs/7000to7099/pdf/nte7089.pdf

BTW, I think there is an error in your circuit diagram. AFAICT, there
is no DC current path from the IC>s output pin and the negative
terminal of the motor.

As for the motor, I would clean out any carbon dust from between the
commutator segments.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.


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