Bourns Pot Shafts Not Long Enough!

[Paul[_13_]]

https://www.mouser.com/datasheet/2/54/tv09-777818.pdf

The length "L" is from where the pot sits on the
PCB board, to the end of the shaft, but it looks
like this L maxes out at 30mm, and I need 35mm.

I'm fairly sure the original is a Bourns pot, because
the bottom of it says "B202", which shows the taper
profile, and the resistance value.

What to do? Maybe I could cut off the tip of the
original shaft, and just epoxy it onto the new one?

[Paul[_13_]]

On 10/12/2018 7:49 PM, Paul wrote:
> https://www.mouser.com/datasheet/2/54/tv09-777818.pdf
>
> The length "L" is from where the pot sits on the
> PCB board, to the end of the shaft, but it looks
> like this L maxes out at 30mm, and I need 35mm.
>
> I'm fairly sure the original is a Bourns pot, because
> the bottom of it says "B202", which shows the taper
> profile, and the resistance value.
>
> What to do?Â* Maybe I could cut off the tip of the
> original shaft, and just epoxy it onto the new one?
>
>

And the longest one that Digikey has in stock, is only 20mm long:


https://www.digikey.com/product-detail/en/bourns-inc/PTV09A-4020F-B202/PTV09A-4020F-B202-ND/3781125

But if I'm gonna epoxy the tip of the old shaft, onto the
new one, it won't matter too much how short the new one is.

[Paul[_13_]]

On 10/12/2018 9:37 PM, Paul wrote:
> On 10/12/2018 7:49 PM, Paul wrote:
>> https://www.mouser.com/datasheet/2/54/tv09-777818.pdf
>>
>> The length "L" is from where the pot sits on the
>> PCB board, to the end of the shaft, but it looks
>> like this L maxes out at 30mm, and I need 35mm.
>>
>> I'm fairly sure the original is a Bourns pot, because
>> the bottom of it says "B202", which shows the taper
>> profile, and the resistance value.
>>
>> What to do?Â* Maybe I could cut off the tip of the
>> original shaft, and just epoxy it onto the new one?
>>
>>
>
> And the longest one that Digikey has in stock, is only 20mm long:
>
>
> https://www.digikey.com/product-detail/en/bourns-inc/PTV09A-4020F-B202/PTV09A-4020F-B202-ND/3781125
>
>
> But if I'm gonna epoxy the tip of the old shaft, onto the
> new one, it won't matter too much how short the new one is.

The alternative, is to just get a panel mounted pot, instead
of a board mounted one like the original. Then I could just screw
it onto the back panel:


https://dt7v1i9vyp3mf.cloudfront.net/styles/news_large/s3/imagelibrary/e/eventmonitors3-talCMpPjwoyOgKxt_VJzG64yNFN9_s1a.jpg

The screw and the washer will partially cover up the -20dB, -5dB,
and MAX indicators that are on the back panel sticker, but the pot will
function the exact same way, and quite possibly will last longer, as the
panel mount pots are bigger.

Any feedback is appreciated.

[Phil Allison[_4_]]

Paul wrote:
>
>
> https://www.mouser.com/datasheet/2/54/tv09-777818.pdf
>
> The length "L" is from where the pot sits on the
> PCB board, to the end of the shaft, but it looks
> like this L maxes out at 30mm, and I need 35mm.
>
> I'm fairly sure the original is a Bourns pot, because
> the bottom of it says "B202", which shows the taper
> profile, and the resistance value.
>

** "B:" ios the cobe letter for "linear and 202 = 2000 ohms.

> What to do? Maybe I could cut off the tip of the
> original shaft, and just epoxy it onto the new one?

** Why not just saw a slot in the top of the new pot and adjust it with a small screwdriver ?.


..... Phil

[Scott Dorsey]

In article >, Paul > wrote:
>What to do? Maybe I could cut off the tip of the
>original shaft, and just epoxy it onto the new one?


Epoxy won't work. Silver solder will for carbon pots, but it's hard not
to damage conductive plastic ones. (I mean hard jeweler's solder, not the
2% kind for Tek scopes).

Back in 1975, you could get replacement pots onesie-twosie from the
shops that catered to TV repair stores, and they came with outrageously
long shafts that you were expected to cut down to size. Those days are
long gone.

Mod-Pot is likely the only solution for longer shafts in onesie-twosies
but you can try doing a search for length on digi-key.

Today just about every pot is a custom item, making replacement a pain.
Which is why I recommend it only as a last resort when cramolin and
rebuilding won't help.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers[_2_]]

On 10/13/2018 9:57 AM, Scott Dorsey wrote:
> Epoxy won't work. Silver solder will for carbon pots, but it's hard not
> to damage conductive plastic ones. (I mean hard jeweler's solder, not the
> 2% kind for Tek scopes).

Another possibility is to get a coupling - a short piece of thick wall
tubing with two set screws - and couple another piece of rod of the
correct diameter to the existing pot shaft. You could cut the shaft off
the old pot that you're replacing and use that as the extension. You may
have to cut off a piece of shaft off the new pot to make room for the
length of the coupling.

Really, though, I was going to suggest what Phil did - cut a slot in the
end of the new pot's shaft to make it screwdriver-adjustable. I take it
this it a replacement for the input gain control on the Event speakers,
so it's not something you'll be changing often.
--

For a good time, call http://mikeriversaudio.wordpress.com

[Bill[_20_]]

In message >, Mike Rivers >
writes
>
>Another possibility is to get a coupling - a short piece of thick wall
>tubing with two set screws - and couple another piece of rod of the
>correct diameter to the existing pot shaft. You could cut the shaft off
>the old pot that you're replacing and use that as the extension. You
>may have to cut off a piece of shaft off the new pot to make room for
>the length of the coupling.
I remember those sleeves, with 4 rather than two set screws.

There appear to be pot shaft extenders of various types on both US and
UK ebay.
--
Bill

---
This email has been checked for viruses by AVG.
https://www.avg.com

[Paul[_13_]]

On 10/13/2018 6:57 AM, Scott Dorsey wrote:
> In article >, Paul > wrote:
>> What to do? Maybe I could cut off the tip of the
>> original shaft, and just epoxy it onto the new one?
>
>
> Epoxy won't work. Silver solder will for carbon pots, but it's hard not
> to damage conductive plastic ones. (I mean hard jeweler's solder, not the
> 2% kind for Tek scopes).
>
> Back in 1975, you could get replacement pots onesie-twosie from the
> shops that catered to TV repair stores, and they came with outrageously
> long shafts that you were expected to cut down to size. Those days are
> long gone.
>
> Mod-Pot is likely the only solution for longer shafts in onesie-twosies
> but you can try doing a search for length on digi-key.
>
> Today just about every pot is a custom item, making replacement a pain.
> Which is why I recommend it only as a last resort when cramolin and
> rebuilding won't help.
> --scott
>

"Rebuilding" as in trying to fix the original pot?

Ok, I've cracked it open. There are two fingers for the variable
resistance wiper, and two for the center pin. I will try to gently
bend these metal fingers up, so that they touch the traces again, and
then clean with the Deoxit Gold that I just bought (the guy at the store
said everyone swears by it!).

I'll let you know how it goes....but that's a good suggestion,
after considering the alternatives!

:)

[Paul[_13_]]

On 10/13/2018 7:21 AM, Mike Rivers wrote:
> On 10/13/2018 9:57 AM, Scott Dorsey wrote:
>> Epoxy won't work.Â* Silver solder will for carbon pots, but it's hard not
>> to damage conductive plastic ones.Â* (I mean hard jeweler's solder, not
>> the
>> 2% kind for Tek scopes).
>
> Another possibility is to get a coupling - a short piece of thick wall
> tubing with two set screws - and couple another piece of rod of the
> correct diameter to the existing pot shaft. You could cut the shaft off
> the old pot that you're replacing and use that as the extension. You may
> have to cut off a piece of shaft off the new pot to make room for the
> length of the coupling.
>
> Really, though, I was going to suggest what Phil did - cut a slot in the
> end of the new pot's shaft to make it screwdriver-adjustable. I take it
> this it a replacement for the input gain control on the Event speakers,
> so it's not something you'll be changing often.

That is correct, this is the sensitivity/gain pot on the Event TR5.

Agreed, I could do that, although the pots that Digikey have in
stock are the "D" type shafts, so that would make it harder to
adjust with a screwdriver.

Plus, re-sale value is lower, when repairs are visible, and the
speakers no longer match.

I'm trying to repair the original pot now....stay tuned!

[Paul[_13_]]

On 10/13/2018 1:07 PM, Paul wrote:
> On 10/13/2018 6:57 AM, Scott Dorsey wrote:
>> In article >, PaulÂ* >
>> wrote:
>>> What to do?Â* Maybe I could cut off the tip of the
>>> original shaft, and just epoxy it onto the new one?
>>
>>
>> Epoxy won't work.Â* Silver solder will for carbon pots, but it's hard not
>> to damage conductive plastic ones.Â* (I mean hard jeweler's solder, not
>> the
>> 2% kind for Tek scopes).
>>
>> Back in 1975, you could get replacement pots onesie-twosie from the
>> shops that catered to TV repair stores, and they came with outrageously
>> long shafts that you were expected to cut down to size.Â* Those days are
>> long gone.
>>
>> Mod-Pot is likely the only solution for longer shafts in onesie-twosies
>> but you can try doing a search for length on digi-key.
>>
>> Today just about every pot is a custom item, making replacement a pain.
>> Which is why I recommend it only as a last resort when cramolin and
>> rebuilding won't help.
>> --scott
>>
>
> Â*Â*Â* "Rebuilding" as in trying to fix the original pot?
>
> Â*Â*Â* Ok, I've cracked it open.Â* There are two fingers for the variable
> resistance wiper, and two for the center pin.Â* I will try to gently
> bend these metal fingers up, so that they touch the traces again, and
> then clean with the Deoxit Gold that I just bought (the guy at the store
> said everyone swears by it!).
>
> Â*Â*Â* I'll let you know how it goes....but that's a good suggestion,
> after considering the alternatives!
>
> Â*Â*Â* :)

Ok, it turns out the wiper fingers are not at fault: The
center pin trace is not connected to the center trace!

There is continuity to both outer pins 1 and 3, but the
center pin 2 is an open, which is somewhere embedded within
the plastic housing!

Dammit! I'm SOL!

:(

[Paul[_13_]]

On 10/13/2018 1:39 PM, Paul wrote:
> On 10/13/2018 1:07 PM, Paul wrote:
>> On 10/13/2018 6:57 AM, Scott Dorsey wrote:
>>> In article >, PaulÂ* >
>>> wrote:
>>>> What to do?Â* Maybe I could cut off the tip of the
>>>> original shaft, and just epoxy it onto the new one?
>>>
>>>
>>> Epoxy won't work.Â* Silver solder will for carbon pots, but it's hard not
>>> to damage conductive plastic ones.Â* (I mean hard jeweler's solder,
>>> not the
>>> 2% kind for Tek scopes).
>>>
>>> Back in 1975, you could get replacement pots onesie-twosie from the
>>> shops that catered to TV repair stores, and they came with outrageously
>>> long shafts that you were expected to cut down to size.Â* Those days are
>>> long gone.
>>>
>>> Mod-Pot is likely the only solution for longer shafts in onesie-twosies
>>> but you can try doing a search for length on digi-key.
>>>
>>> Today just about every pot is a custom item, making replacement a pain.
>>> Which is why I recommend it only as a last resort when cramolin and
>>> rebuilding won't help.
>>> --scott
>>>
>>
>> Â*Â*Â*Â* "Rebuilding" as in trying to fix the original pot?
>>
>> Â*Â*Â*Â* Ok, I've cracked it open.Â* There are two fingers for the variable
>> resistance wiper, and two for the center pin.Â* I will try to gently
>> bend these metal fingers up, so that they touch the traces again, and
>> then clean with the Deoxit Gold that I just bought (the guy at the store
>> said everyone swears by it!).
>>
>> Â*Â*Â*Â* I'll let you know how it goes....but that's a good suggestion,
>> after considering the alternatives!
>>
>> Â*Â*Â*Â* :)
>
> Â*Â*Â*Â*Â*Â* Ok, it turns out the wiper fingers are not at fault:Â* The
> center pin trace is not connected to the center trace!
>
> Â*Â*Â*Â*Â*Â* There is continuity to both outer pins 1 and 3, but the
> center pin 2 is an open, which is somewhere embedded within
> the plastic housing!
>
> Â*Â*Â*Â*Â*Â* Dammit!Â* I'm SOL!
>
> Â*Â*Â*Â*Â*Â* :(

Ok, since I'm pretty sure this original pot is a Bourns one,
because the dimensions are very close, would it be possible to buy
a new pot, and replace the too-short shaft with the older, longer
shaft? The wiper/finger metal looks to be in good shape still.

Has anyone ever successfully done this before?

[Scott Dorsey]

In article >, Paul > wrote:
> "Rebuilding" as in trying to fix the original pot?
>
> Ok, I've cracked it open. There are two fingers for the variable
>resistance wiper, and two for the center pin. I will try to gently
>bend these metal fingers up, so that they touch the traces again, and
>then clean with the Deoxit Gold that I just bought (the guy at the store
>said everyone swears by it!).

Before doing that, you should have tried just squirting some cleaner in there.
There's seldom any need to actually take the pot apart.

You don't want the Deoxit Gold, you want the less aggressive stuff that has
a lubricant in it, like FaderLube, which is also a Caig product and should
have been on the same shelf. But try the gold cleaner and see.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article >, Paul > wrote:
> Ok, it turns out the wiper fingers are not at fault: The
>center pin trace is not connected to the center trace!
>
> There is continuity to both outer pins 1 and 3, but the
>center pin 2 is an open, which is somewhere embedded within
>the plastic housing!

Yes, because the moving contact point is gunked up. Flush the whole thing
with cramolin and it will likely be fine. Spray it in, work it back and
forth, spray some more, work it back and forth.

> Dammit! I'm SOL!

No, you aren't. You should just follow the advice I gave in my first message
and flush the thing out with cramolin. Or Callube or FaderLube, or, as I said,
whatever the currently fashionable Quietrole replacement is.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Paul[_13_]]

On 10/13/2018 2:29 PM, Scott Dorsey wrote:
> In article >, Paul > wrote:
>> Ok, it turns out the wiper fingers are not at fault: The
>> center pin trace is not connected to the center trace!
>>
>> There is continuity to both outer pins 1 and 3, but the
>> center pin 2 is an open, which is somewhere embedded within
>> the plastic housing!
>
> Yes, because the moving contact point is gunked up. Flush the whole thing
> with cramolin and it will likely be fine. Spray it in, work it back and
> forth, spray some more, work it back and forth.
>
>> Dammit! I'm SOL!
>
> No, you aren't. You should just follow the advice I gave in my first message
> and flush the thing out with cramolin. Or Callube or FaderLube, or, as I said,
> whatever the currently fashionable Quietrole replacement is.
> --scott
>

No, you are misunderstand the situation.

With the wiper and shaft taken off, there are two traces on the
pot: one trace for the variable resistance, and one trace for the
center pin. The trace for the center pin is NOT connected to pin 2.

There is an open there, and it's somewhere embedded inside
the plastic moulding. There's nothing I can do with it, without
destroying it.

I have ordered a few of the 2K Bourns pots, with the intention
of taking apart one of them, and seeing if I can replace the too-short
new shaft, with the older, but longer shaft.

It might work. If it doesn't, I'll just cut a slot in the shaft,
and use a screwdriver to adjust it, as has been suggested.

Stay tuned.

[geoff]

On 14/10/2018 3:21 AM, Mike Rivers wrote:
> On 10/13/2018 9:57 AM, Scott Dorsey wrote:
>> Epoxy won't work.Â* Silver solder will for carbon pots, but it's hard not
>> to damage conductive plastic ones.Â* (I mean hard jeweler's solder, not
>> the
>> 2% kind for Tek scopes).
>
> Another possibility is to get a coupling - a short piece of thick wall
> tubing with two set screws - and couple another piece of rod of the
> correct diameter to the existing pot shaft. You could cut the shaft off
> the old pot that you're replacing and use that as the extension. You may
> have to cut off a piece of shaft off the new pot to make room for the
> length of the coupling.
>
> Really, though, I was going to suggest what Phil did - cut a slot in the
> end of the new pot's shaft to make it screwdriver-adjustable. I take it
> this it a replacement for the input gain control on the Event speakers,
> so it's not something you'll be changing often.


Or would a countersunk or different knob somehow reach the shaft. may
have to enlarge the panel-hole if pcb-mounted pot.

geoff

[geoff]

On 14/10/2018 9:07 AM, Paul wrote:
> On 10/13/2018 6:57 AM, Scott Dorsey wrote:
>> In article >, PaulÂ* >
>> wrote:
>>> What to do?Â* Maybe I could cut off the tip of the
>>> original shaft, and just epoxy it onto the new one?
>>
>>
>> Epoxy won't work.Â* Silver solder will for carbon pots, but it's hard not
>> to damage conductive plastic ones.Â* (I mean hard jeweler's solder, not
>> the
>> 2% kind for Tek scopes).
>>
>> Back in 1975, you could get replacement pots onesie-twosie from the
>> shops that catered to TV repair stores, and they came with outrageously
>> long shafts that you were expected to cut down to size.Â* Those days are
>> long gone.
>>
>> Mod-Pot is likely the only solution for longer shafts in onesie-twosies
>> but you can try doing a search for length on digi-key.
>>
>> Today just about every pot is a custom item, making replacement a pain.
>> Which is why I recommend it only as a last resort when cramolin and
>> rebuilding won't help.
>> --scott
>>
>
> Â*Â*Â* "Rebuilding" as in trying to fix the original pot?
>
> Â*Â*Â* Ok, I've cracked it open.Â* There are two fingers for the variable
> resistance wiper, and two for the center pin.Â* I will try to gently
> bend these metal fingers up, so that they touch the traces again, and
> then clean with the Deoxit Gold that I just bought (the guy at the store
> said everyone swears by it!).
>
> Â*Â*Â* I'll let you know how it goes....but that's a good suggestion,
> after considering the alternatives!
>
> Â*Â*Â* :)


DeOxit Gold is great for what it's for, but treating/lubing pots isn't it.

You need Caig FaderLube, or whatever it's current name is. It is a
totally different thing to DeOxit Gold.

geoff

[Scott Dorsey]

In article >, Paul > wrote:
> No, you are misunderstand the situation.
>
> With the wiper and shaft taken off, there are two traces on the
>pot: one trace for the variable resistance, and one trace for the
>center pin. The trace for the center pin is NOT connected to pin 2.

Right. There is a contact connected to the center pin which touches that
trace. But the contact is bad, or that trace is dirty.

Sometimes instead of having that second trace, there is a contact that
connects to the side of the rotating shaft in order to provide the
connection to the sliding element.

Remember: the sliding element moves, the pin is static. Therefore there
is a moving contact between the two. Moving contacts go bad.

> There is an open there, and it's somewhere embedded inside
>the plastic moulding. There's nothing I can do with it, without
>destroying it.

There's an open there. Flood it with cramolin. Get cramolin behind the
plastic molding. Everything that moves, get cramolin on it. Just pump it
full until it comes squirting out. You can usually do this without taking
the pot apart.

What you are describing is one of the more common pot failure modes.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Phil Allison[_4_]]

Paul wrote:
>
>

>
> I have ordered a few of the 2K Bourns pots, with the intention
> of taking apart one of them, and seeing if I can replace the too-short
> new shaft, with the older, but longer shaft.
>

** That seems worth a try.


> It might work. If it doesn't, I'll just cut a slot in the shaft,
> and use a screwdriver to adjust it, as has been suggested.
>


** Once came across some fancy pots that uses 1/8inch metal shafts - but original knobs were missing.

So, I converted /4 inch, plastic knitting needles into sleeves by drilling 1/8 inch holes up the centre of a few short pieces. Standard knobs then fitted fine.



..... Phil

[Paul[_13_]]

On 10/13/2018 5:17 PM, Scott Dorsey wrote:
> In article >, Paul > wrote:
>> No, you are misunderstand the situation.
>>
>> With the wiper and shaft taken off, there are two traces on the
>> pot: one trace for the variable resistance, and one trace for the
>> center pin. The trace for the center pin is NOT connected to pin 2.
>
> Right. There is a contact connected to the center pin which touches that
> trace. But the contact is bad, or that trace is dirty.
>
> Sometimes instead of having that second trace, there is a contact that
> connects to the side of the rotating shaft in order to provide the
> connection to the sliding element.
>
> Remember: the sliding element moves, the pin is static. Therefore there
> is a moving contact between the two. Moving contacts go bad.
>
>> There is an open there, and it's somewhere embedded inside
>> the plastic moulding. There's nothing I can do with it, without
>> destroying it.
>
> There's an open there. Flood it with cramolin. Get cramolin behind the
> plastic molding. Everything that moves, get cramolin on it. Just pump it
> full until it comes squirting out. You can usually do this without taking
> the pot apart.
>
> What you are describing is one of the more common pot failure modes.

No, there's nothing more can do at this point, which is why I
ordered new pots.

Look at this pic:


https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ

See the center ring? That's supposed to be connected
to the center pin. In my case, it's an open, and unlike
this picture, the trace disappears into the plastic moulding.

The ring itself is clean, and has good continuity, but there is an
open EMBEDDED INSIDE THE PLASTIC. I could try to break the plastic
apart, but then the whole thing will be toast!

I think my chances are decent, to replace a new shaft with the old
one.

[Scott Dorsey]

In article >, Paul > wrote:
>
>https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>
> See the center ring? That's supposed to be connected
>to the center pin. In my case, it's an open, and unlike
>this picture, the trace disappears into the plastic moulding.
>
> The ring itself is clean, and has good continuity, but there is an
>open EMBEDDED INSIDE THE PLASTIC. I could try to break the plastic
>apart, but then the whole thing will be toast!

This is typical construction; there is a rivet used to make the connection
betwen the phenolic board and the pin. What happens is that the rivet
contact corrodes and becomes open. Guess what you can do in order to clean
that up?

Just because the contact is embedded in the plastic doesn't mean it can't be
cleaned up.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Paul[_13_]]

On 10/15/2018 6:48 AM, Scott Dorsey wrote:
> In article >, Paul > wrote:
>>
>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>
>> See the center ring? That's supposed to be connected
>> to the center pin. In my case, it's an open, and unlike
>> this picture, the trace disappears into the plastic moulding.
>>
>> The ring itself is clean, and has good continuity, but there is an
>> open EMBEDDED INSIDE THE PLASTIC. I could try to break the plastic
>> apart, but then the whole thing will be toast!
>
> This is typical construction; there is a rivet used to make the connection
> betwen the phenolic board and the pin. What happens is that the rivet
> contact corrodes and becomes open. Guess what you can do in order to clean
> that up?
>
> Just because the contact is embedded in the plastic doesn't mean it can't be
> cleaned up.

I have tried flooding it with contact cleaner, and still no go.

Contact cleaner is NOT going to bridge an open gap between
conductors. There are limits!

But it's a moot point now....New pots from Mouser!

[geoff]

On 16/10/2018 2:48 AM, Scott Dorsey wrote:
> In article >, Paul > wrote:
>>
>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>
>> See the center ring? That's supposed to be connected
>> to the center pin. In my case, it's an open, and unlike
>> this picture, the trace disappears into the plastic moulding.
>>
>> The ring itself is clean, and has good continuity, but there is an
>> open EMBEDDED INSIDE THE PLASTIC. I could try to break the plastic
>> apart, but then the whole thing will be toast!
>
> This is typical construction; there is a rivet used to make the connection
> betwen the phenolic board and the pin. What happens is that the rivet
> contact corrodes and becomes open. Guess what you can do in order to clean
> that up?
>
> Just because the contact is embedded in the plastic doesn't mean it can't be
> cleaned up.
> --scott
>


I've had luck (luck that it 'took') simply flowing solder from the rivet
to the metalised track.

Should conside that as short-term relief only, and may or may not work
with some makes of pot.

geoff

[Chuck[_11_]]

On Tue, 16 Oct 2018 07:54:47 +1300, geoff >
wrote:

>On 16/10/2018 2:48 AM, Scott Dorsey wrote:
>> In article >, Paul > wrote:
>>>
>>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>>
>>> See the center ring? That's supposed to be connected
>>> to the center pin. In my case, it's an open, and unlike
>>> this picture, the trace disappears into the plastic moulding.
>>>
>>> The ring itself is clean, and has good continuity, but there is an
>>> open EMBEDDED INSIDE THE PLASTIC. I could try to break the plastic
>>> apart, but then the whole thing will be toast!
>>
>> This is typical construction; there is a rivet used to make the connection
>> betwen the phenolic board and the pin. What happens is that the rivet
>> contact corrodes and becomes open. Guess what you can do in order to clean
>> that up?
>>
>> Just because the contact is embedded in the plastic doesn't mean it can't be
>> cleaned up.
>> --scott
>>
>
>
>I've had luck (luck that it 'took') simply flowing solder from the rivet
>to the metalised track.
>
>Should conside that as short-term relief only, and may or may not work
>with some makes of pot.
>
>geoff
Sometimes conductive paint works to repair this issue.

[Paul[_13_]]

On 10/15/2018 12:17 PM, Chuck wrote:
> On Tue, 16 Oct 2018 07:54:47 +1300, geoff >
> wrote:
>
>> On 16/10/2018 2:48 AM, Scott Dorsey wrote:
>>> In article >, Paul > wrote:
>>>>
>>>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>>>
>>>> See the center ring? That's supposed to be connected
>>>> to the center pin. In my case, it's an open, and unlike
>>>> this picture, the trace disappears into the plastic moulding.
>>>>
>>>> The ring itself is clean, and has good continuity, but there is an
>>>> open EMBEDDED INSIDE THE PLASTIC. I could try to break the plastic
>>>> apart, but then the whole thing will be toast!
>>>
>>> This is typical construction; there is a rivet used to make the connection
>>> betwen the phenolic board and the pin. What happens is that the rivet
>>> contact corrodes and becomes open. Guess what you can do in order to clean
>>> that up?
>>>
>>> Just because the contact is embedded in the plastic doesn't mean it can't be
>>> cleaned up.
>>> --scott
>>>
>>
>>
>> I've had luck (luck that it 'took') simply flowing solder from the rivet
>> to the metalised track.
>>
>> Should conside that as short-term relief only, and may or may not work
>> with some makes of pot.
>>
>> geoff
> Sometimes conductive paint works to repair this issue.
>

Either solder or conductive paint will not work in this
case. Again, my case is different than the photo I posted,
as the trace and the center pin connection is embedded within
the plastic housing of the pot.

I could conceivably break open the casing, but then
the pot would be destroyed!

So brand new post are on the way from Mouser.

[Paul[_13_]]

On 10/15/2018 7:02 PM, Paul wrote:
> On 10/15/2018 12:17 PM, Chuck wrote:
>> On Tue, 16 Oct 2018 07:54:47 +1300, geoff >
>> wrote:
>>
>>> On 16/10/2018 2:48 AM, Scott Dorsey wrote:
>>>> In article >, Paul
>>>> > wrote:
>>>>>
>>>>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>>>>
>>>>>
>>>>> Â*Â*Â*Â*Â*Â* See the center ring?Â* That's supposed to be connected
>>>>> to the center pin.Â* In my case, it's an open, and unlike
>>>>> this picture, the trace disappears into the plastic moulding.
>>>>>
>>>>> Â*Â*Â*Â*Â*Â* The ring itself is clean, and has good continuity, but there
>>>>> is an
>>>>> open EMBEDDED INSIDE THE PLASTIC.Â* I could try to break the plastic
>>>>> apart, but then the whole thing will be toast!
>>>>
>>>> This is typical construction; there is a rivet used to make the
>>>> connection
>>>> betwen the phenolic board and the pin.Â* What happens is that the rivet
>>>> contact corrodes and becomes open.Â* Guess what you can do in order
>>>> to clean
>>>> that up?
>>>>
>>>> Just because the contact is embedded in the plastic doesn't mean it
>>>> can't be
>>>> cleaned up.
>>>> --scott
>>>>
>>>
>>>
>>> I've had luck (luck that it 'took') simply flowing solder from the rivet
>>> to the metalised track.
>>>
>>> Should conside that as short-term relief only, and may or may not work
>>> with some makes of pot.
>>>
>>> geoff
>> Sometimes conductive paint works to repair this issue.
>>
>
> Â*Â*Â*Â* Either solder or conductive paint will not work in this
> case.Â* Again, my case is different than the photo I posted,
> as the trace and the center pin connection is embedded within
> the plastic housing of the pot.
>
> Â*Â*Â*Â* I could conceivably break open the casing, but then
> the pot would be destroyed!
>
> Â*Â*Â*Â* So brand new post are on the way from Mouser.

Brand new POTS are on the way!

:)

[Paul[_13_]]

On 10/15/2018 7:03 PM, Paul wrote:
> On 10/15/2018 7:02 PM, Paul wrote:
>> On 10/15/2018 12:17 PM, Chuck wrote:
>>> On Tue, 16 Oct 2018 07:54:47 +1300, geoff >
>>> wrote:
>>>
>>>> On 16/10/2018 2:48 AM, Scott Dorsey wrote:
>>>>> In article >, Paul
>>>>> > wrote:
>>>>>>
>>>>>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>>>>>
>>>>>>
>>>>>> Â*Â*Â*Â*Â*Â* See the center ring?Â* That's supposed to be connected
>>>>>> to the center pin.Â* In my case, it's an open, and unlike
>>>>>> this picture, the trace disappears into the plastic moulding.
>>>>>>
>>>>>> Â*Â*Â*Â*Â*Â* The ring itself is clean, and has good continuity, but
>>>>>> there is an
>>>>>> open EMBEDDED INSIDE THE PLASTIC.Â* I could try to break the plastic
>>>>>> apart, but then the whole thing will be toast!
>>>>>
>>>>> This is typical construction; there is a rivet used to make the
>>>>> connection
>>>>> betwen the phenolic board and the pin.Â* What happens is that the rivet
>>>>> contact corrodes and becomes open.Â* Guess what you can do in order
>>>>> to clean
>>>>> that up?
>>>>>
>>>>> Just because the contact is embedded in the plastic doesn't mean it
>>>>> can't be
>>>>> cleaned up.
>>>>> --scott
>>>>>
>>>>
>>>>
>>>> I've had luck (luck that it 'took') simply flowing solder from the
>>>> rivet
>>>> to the metalised track.
>>>>
>>>> Should conside that as short-term relief only, and may or may not work
>>>> with some makes of pot.
>>>>
>>>> geoff
>>> Sometimes conductive paint works to repair this issue.
>>>
>>
>> Â*Â*Â*Â*Â* Either solder or conductive paint will not work in this
>> case.Â* Again, my case is different than the photo I posted,
>> as the trace and the center pin connection is embedded within
>> the plastic housing of the pot.
>>
>> Â*Â*Â*Â*Â* I could conceivably break open the casing, but then
>> the pot would be destroyed!
>>
>> Â*Â*Â*Â*Â* So brand new post are on the way from Mouser.
>
> Â*Â*Â*Â* Brand new POTS are on the way!
>

It worked! I was able to disassemble one of the new
2K Bourns pots that I got from Mouser, and the old, long shaft
fit perfectly! Thank god they kept the same footprint and
shaft dimensions!

Listen to Dark side of the moon, with my "new"
speakers!

Thanks for the feedback, everyone!

:)

[geoff]

On 20/10/2018 3:58 PM, Paul wrote:
> On 10/15/2018 7:03 PM, Paul wrote:
>> On 10/15/2018 7:02 PM, Paul wrote:
>>> On 10/15/2018 12:17 PM, Chuck wrote:
>>>> On Tue, 16 Oct 2018 07:54:47 +1300, geoff >
>>>> wrote:
>>>>
>>>>> On 16/10/2018 2:48 AM, Scott Dorsey wrote:
>>>>>> In article >, Paul
>>>>>> > wrote:
>>>>>>>
>>>>>>> https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ92tHCnEf-oAB8GWPwOrB3dcJM1p_f8ftS6OknNGiz_quRoJu2nQ
>>>>>>>
>>>>>>>
>>>>>>> Â*Â*Â*Â*Â*Â* See the center ring?Â* That's supposed to be connected
>>>>>>> to the center pin.Â* In my case, it's an open, and unlike
>>>>>>> this picture, the trace disappears into the plastic moulding.
>>>>>>>
>>>>>>> Â*Â*Â*Â*Â*Â* The ring itself is clean, and has good continuity, but
>>>>>>> there is an
>>>>>>> open EMBEDDED INSIDE THE PLASTIC.Â* I could try to break the plastic
>>>>>>> apart, but then the whole thing will be toast!
>>>>>>
>>>>>> This is typical construction; there is a rivet used to make the
>>>>>> connection
>>>>>> betwen the phenolic board and the pin.Â* What happens is that the
>>>>>> rivet
>>>>>> contact corrodes and becomes open.Â* Guess what you can do in order
>>>>>> to clean
>>>>>> that up?
>>>>>>
>>>>>> Just because the contact is embedded in the plastic doesn't mean
>>>>>> it can't be
>>>>>> cleaned up.
>>>>>> --scott
>>>>>>
>>>>>
>>>>>
>>>>> I've had luck (luck that it 'took') simply flowing solder from the
>>>>> rivet
>>>>> to the metalised track.
>>>>>
>>>>> Should conside that as short-term relief only, and may or may not work
>>>>> with some makes of pot.
>>>>>
>>>>> geoff
>>>> Sometimes conductive paint works to repair this issue.
>>>>
>>>
>>> Â*Â*Â*Â*Â* Either solder or conductive paint will not work in this
>>> case.Â* Again, my case is different than the photo I posted,
>>> as the trace and the center pin connection is embedded within
>>> the plastic housing of the pot.
>>>
>>> Â*Â*Â*Â*Â* I could conceivably break open the casing, but then
>>> the pot would be destroyed!
>>>
>>> Â*Â*Â*Â*Â* So brand new post are on the way from Mouser.
>>
>> Â*Â*Â*Â*Â* Brand new POTS are on the way!
>>
>
> Â*Â*Â*Â*Â* It worked!Â* I was able to disassemble one of the new
> 2K Bourns pots that I got from Mouser, and the old, long shaft
> fit perfectly!Â* Thank god they kept the same footprint and
> shaft dimensions!
>
> Â*Â*Â*Â*Â* Listen to Dark side of the moon, with my "new"
> speakers!

While in a 'moon' frame of mind, try a listen to Supertramp "Some Things
Never Change" . A good workout (in many different ways) for any speaker,
and great music.

Jack Douglas,Fred Mandel,Jay Messina on the production/engineering side.

geoff