Need help identifying a potentiometer

[bryanska]

Hello, I pulled a part from my stereo that needs to be replaced. I
figured it was the potentiometer, because the sound was crackling.

When I pulled the assembly, it was TWO potentiometers, linked together.
There is a shaft running through them. I don't have ANY idea where I
can find a replacement. The JVC repair site lists the larger assembly
at $59.

I have posted pictures on my website, in the links below.

Please help me identify these two pots, and any tips on where I can
find replacements. I will be VERY grateful.

Also, how can I tell which replacement pots to buy? I don't see a
universal code that tells which voltage/etc., like resistors have.

http://www.theevilwebsite.com/blog/_archives/2006/12/26/2598747.html

http://www.theevilwebsite.com/blog/_archives/2006/12/26/2598750.html

http://www.theevilwebsite.com/blog/_archives/2006/12/26/2598751.html

http://www.theevilwebsite.com/blog/_archives/2006/12/26/2598756.html

http://www.theevilwebsite.com/blog/_archives/2006/12/26/2598761.html

 

[bryanska]

OK I see that these are dual-gang pots. I found that out.

But there are two linked together? Where can I find those?

Also, why does on pot (the forwardmost one) have only one set of three
pegs?

And I haven't found four-pegged pots, like the one in the rear. Why
does it have four?

Again, any help is welcome.

 

[Dave Platt]

In article <1167173532.332873.133810@i12g2000cwa.googlegroups.com>,
bryanska <BARRELBACK@HOTMAIL.COM> wrote:

Hello, I pulled a part from my stereo that needs to be replaced. I
figured it was the potentiometer, because the sound was crackling.

When I pulled the assembly, it was TWO potentiometers, linked together.
There is a shaft running through them. I don't have ANY idea where I
can find a replacement. The JVC repair site lists the larger assembly
at $59.

It's probably custom-fabricated for this particular product. The
individual subsections are probably not all that unusual, but the
combination is likely unique to this one product line.

The two four-contact sections are probably a pair of linear-taper
potentiometers with a fixed tap (the tap being used for the "loudness"
circuit). The three-pegger in the front might be a switch, or might
be a linear-taper pot which is used to read out the control's
rotational position so that the remote control management circuitry
can "servo" the pot to the desired location.

You might want to try giving each of the potentiometer sections a good
cleaning, using a low- or no-residue contact/control cleaning spray,
or perhaps one which is designed to clean the contacts and then leave
a very small amount of lubricant on the potentiometer surface. This
*might* restore the control quality enough to get rid of the crackly
sound.

If that doesn't work, and if you decide that you do need to replace
the control, I think you're probably going to have to just buy the
whole replacement module from JVC for their asking price. Although it
might be possible to cobble together a custom replacement from
off-the-shelf parts, I think that you'd probably have a very
frustrating time indeed trying to put together the necessary set of
components, and would likely have to do enough adaptation and
refitting that you'd end up with a basket of snakes.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

[Lostgallifreyan]

"bryanska" <BARRELBACK@HOTMAIL.COM> wrote in
news:1167173532.332873.133810@i12g2000cwa.googlegroups.com:

Hello, I pulled a part from my stereo that needs to be replaced.

How hard did you pull it, exactly? That bent and broken metal looks like a
lost cause to me. Cleaning the pots with a small flush of isopropyl alcohol
might have been all that was needed, but now you'll need the original
assembly complete with the mounting bracket to get things right. You might
find a pair of dual-ganged pots on one shaft, and use half of one of them,
but you'd have to get a A law (log) pot for audio, and if you wanted the
remote volume control to work, you'll have to figure out a way to get the
gear attached and connected to the motor drive, and a flat on the spindle
appropriate to the original knob.

Beleive me, pay what JVC want. It's far easier to raise that money than to
make this work any other way. Pay it and don't look back.

 

[Peter Bennett]

On 26 Dec 2006 14:52:12 -0800, "bryanska" <BARRELBACK@HOTMAIL.COM>
wrote:

Hello, I pulled a part from my stereo that needs to be replaced. I
figured it was the potentiometer, because the sound was crackling.

When I pulled the assembly, it was TWO potentiometers, linked together.
There is a shaft running through them. I don't have ANY idea where I
can find a replacement. The JVC repair site lists the larger assembly
at $59.

I have posted pictures on my website, in the links below.

Please help me identify these two pots, and any tips on where I can
find replacements. I will be VERY grateful.

Looks to me as if it is a custom assembly. There may be four
resistance elements (the brown wafers), interconnected in some special
way.

I expect that the only source for a direct replacement would be JVC.
If you had a wiring diagram for the stereo, and sufficient knowledge,
you may be able to find a usable substitute, but it likely wouldn't
work quite the same, and probably couldn't be motor-driven.



--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[bryanska]

How hard did you pull it, exactly? That bent and broken metal looks like a
lost cause to me. Cleaning the pots with a small flush of isopropyl alcohol
might have been all that was needed, but now you'll need the original
assembly complete with the mounting bracket to get things right. You might
find a pair of dual-ganged pots on one shaft, and use half of one of them,
but you'd have to get a A law (log) pot for audio, and if you wanted the
remote volume control to work, you'll have to figure out a way to get the
gear attached and connected to the motor drive, and a flat on the spindle
appropriate to the original knob.

Beleive me, pay what JVC want. It's far easier to raise that money than to
make this work any other way. Pay it and don't look back.

Thanks for the advice all.

I searched ALL over the Net and couldn't find any generic part close to
this.

I wasn't concerned about the bent metal. That was an easy "loss" which
allowed me to gently pull the delicate pieces apart.

So I dissected it, having given up on finding a cheap replacement. It
was indeed very custom, as the shaft proceeded through the first pot,
and through the second, to terminate in the gear assembly.

I am going to try to contact a representative at the JVC parts house
and fanagle a lowball offer on the assembly. The stereo itself is an
older model built in 1991. My father paid an exorbitant sum and kept
the unit in flawless shape. It's a shame that some tiny, otherwise
cheap copper contacts will bring down what's really a glorious system.
It was one of the first "shelf" size systems.

Thank you everyone for your advice! What a helpful group.