Toshiba TV29C90 problem; Image fades to black...

[Simoc]

Michael A. Terrell kirjoitti:

So, you want everyone on Usenet to do things your way so you can use
a cheap piece of crap?

And moreover, top-posting doesn't help even in that case. When only
necessary part of quote is included, bottom-posting shouldn't cause
problem even with that cheap piece of crap And necessary is
necessary. I think that triple scrolling (to see the necessary quote
first and then the reply) 'd be far more difficult with such PDA.

--
Top-posting not supported.

 

[David Forsyth]

Wow this is exactly the info I was looking for - thank you so much! The
toner is the trick. I was thinking of trying to bind it with epoxy
but I like the toner idea better. Do you think a heat gun would work in
fusing the film onto the backing or would that be too hot or too
inconsistant?
In any case I have a place to start now - thanks again!

Dave


"N Cook" <diverse8@gazeta.pl> wrote in message
news:eqk3vb$rhk$1@inews.gazeta.pl...

David Forsyth <Polaris30@epix.net> wrote in message
news:_15zh.2590$Oc.157540@news1.epix.net...
I have a need to rebuild some slide pots from 1970's musical equipment
snip

on one of my 2 tips files, URL below, is a formulation ofphotocopier toner
and graphite i have used in such circumstances. Otherwise if only thin
wipers , dismantle and move the wipers to fresh bits of track.


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

 

[N Cook]

David Forsyth <Polaris30@epix.net> wrote in message
news:LLkzh.2608$Oc.157743@news1.epix.net...

Wow this is exactly the info I was looking for - thank you so much! The
toner is the trick. I was thinking of trying to bind it with epoxy
but I like the toner idea better. Do you think a heat gun would work in
fusing the film onto the backing or would that be too hot or too
inconsistant?
In any case I have a place to start now - thanks again!

Dave


"N Cook" <diverse8@gazeta.pl> wrote in message
news:eqk3vb$rhk$1@inews.gazeta.pl...
David Forsyth <Polaris30@epix.net> wrote in message
news:_15zh.2590$Oc.157540@news1.epix.net...
I have a need to rebuild some slide pots from 1970's musical equipment
snip


on one of my 2 tips files, URL below, is a formulation of photocopier
toner
and graphite i have used in such circumstances. Otherwise if only thin
wipers , dismantle and move the wipers to fresh bits of track.


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

toner and graphite are both fine dust

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

 

[David Forsyth]

ahh ok - for whatever reason I was thinking toner was a fluid - thanks
again!

Dave


"N Cook" <diverse8@gazeta.pl> wrote in message
news:eqkp68$8l2$1@inews.gazeta.pl...

David Forsyth <Polaris30@epix.net> wrote in message
news:LLkzh.2608$Oc.157743@news1.epix.net...
Wow this is exactly the info I was looking for - thank you so much! The
toner is the trick. I was thinking of trying to bind it with epoxy
but I like the toner idea better. Do you think a heat gun would work in
fusing the film onto the backing or would that be too hot or too
inconsistant?
In any case I have a place to start now - thanks again!

Dave


"N Cook" <diverse8@gazeta.pl> wrote in message
news:eqk3vb$rhk$1@inews.gazeta.pl...
David Forsyth <Polaris30@epix.net> wrote in message
news:_15zh.2590$Oc.157540@news1.epix.net...
I have a need to rebuild some slide pots from 1970's musical equipment
snip


on one of my 2 tips files, URL below, is a formulation of photocopier
toner
and graphite i have used in such circumstances. Otherwise if only thin
wipers , dismantle and move the wipers to fresh bits of track.


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





toner and graphite are both fine dust

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

 

[Spehro Pefhany]

On Fri, 09 Feb 2007 20:43:38 GMT, the renowned "David Forsyth"
<Polaris30@epix.net> wrote:

I have a need to rebuild some slide pots from 1970's musical equipment that
have worn-through resistance strips. The pots are long since unobtainable
(made by CTS), and I have yet to find any suitable replacements. The
resistance strips inside the pots are removable, and consist of a die-cut
non-conductive substrate onto which a carbon resistance compound was bound
and on which the slide contact of the pot slides. Each end of the strip has
a metal connnector crimped to it to serve as an end terminal for the pot.

I think if I knew what kind of binder and process is commonly used to adhere
the carbon to the substrate I could restore the resistance layer. It would
most likely have to be baked onto the strip, which is not a problem. For
the resistance material itself, I was thinking of using material from carbon
comp resistors (it would be trial and error to find the right value for this
application). So, I am trying to find information on how resistance
material is bound to a substrate for use in wiper/pot applications (it would
have to be fairly resistant to abrasion, solvents, etc.) Please email
foda01 at epix dot net with any helpful info.

thanks,

Dave

Okay, well, many years ago I did some work along these lines. It's not
all that difficult. CTS used to make some custom pots for us (very
high resistance)-- they're right nearby, but I think they are
concentrating on high-volume commercial/automotive sensor applications
these days.

You need to make the substrate (typically a paper-based phenolic). It
would have been stamped originally.. the die would cost a pretty
penny, but maybe you could get it cut using soft tooling with water
jet or something like that (I imagine laser cutting would release some
very unpleasant fumes).

The resistive ink is then silk(sic)-screened on. You create the
artwork and have a screen made at a supplier. It probably ought to be
a stainless mesh in a metal frame. You will need the proper ink and to
follow the manufacturer's recommendations as to what thinner to use
and what screen cleaning chemicals to use. Communicate that
information to the screen maker in advance so they can use the proper
'hardening' depending on how harsh the solvents are. (Use a proper
industrial screen supply house, not a T-shirt type operation).

You will need a proper manual screening setup to hold the substrate in
place. The gap between screen and substrate is critical to getting the
thickness (and thus cross-sectional area, and thus resistance) within
tolerance. It will probably take some experimentation to get within
the 20-30% tolerance range, but trimming should not be necessary. The
connections at the ends, I think, are typically made with crimped in
riveted connections with a silver-bearing conductive ink or epoxy
gobbed on around the rivet. You can probably get this material from
the same supplier as the resistive ink. I don't recall the suppliers
for this stuff, you're probably going to have to research it.

You have to bake the element to cure it (possibly before attaching the
end connections) with a specified time-temperature profile, so you'd
need a small oven for that. It won't be very high temperature, since
the substrate can't take high temperatures. Maybe 400°F for an hour.

If you can sell 100 of them @ $100 each it might even be worth doing.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Michael A. Terrell]

Simoc wrote:

Michael A. Terrell kirjoitti:
So, you want everyone on Usenet to do things your way so you can use
a cheap piece of crap?

And moreover, top-posting doesn't help even in that case. When only
necessary part of quote is included, bottom-posting shouldn't cause
problem even with that cheap piece of crap And necessary is
necessary. I think that triple scrolling (to see the necessary quote
first and then the reply) 'd be far more difficult with such PDA.

--
Top-posting not supported.

Some people go WAY out of their way to do things wrong. A few years
ago, it was using video games to access the net, then bitching that
everyone should make sure their content could be accessed by their
cobbled together junk.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Homer J Simpson]

"N Cook" <diverse8@gazeta.pl> wrote in message
news:eqkp68$8l2$1@inews.gazeta.pl...

toner and graphite are both fine dust

But toner is ground hotmelt glue with some iron oxide IIRC.

 

[N Cook]

Homer J Simpson <nobody@nowhere.com> wrote in message
news:Ceozh.42428$Fd.16360@edtnps90...

"N Cook" <diverse8@gazeta.pl> wrote in message
news:eqkp68$8l2$1@inews.gazeta.pl...

toner and graphite are both fine dust

But toner is ground hotmelt glue with some iron oxide IIRC.

iron in the form of iron filings is used in the process but not consumed ,
even used in laser printers, no better process would seem to have been found
for the "developer" that transfers the toner to the OPC.

some notes of mine on copiers
http://www.divdev.fsnet.co.uk/copiers.htm

 

[Arfa Daily]

"David Forsyth" <Polaris30@epix.net> wrote in message
news:0Zazh.2605$Oc.157593@news1.epix.net...

Hi everyone -

first off sorry for the confusion - I didnt mean to imply I wouldnt be
checking back into the newsgroup, I just never know when I can get online
and sometimes the older messages dont show up in my listings.

second - good idea about the conductive polymer - I hadnt thought along
those lines yet.

The travel on these pots is 2 inches and the closest thing I could find is
an alpha part but the construction is completely different internally and
they dont offer all of the various values I would need. I wonder if I
could have a lot of them custom made but I dont have megabucks to invest.
These are for synths and there is a demand since the NOS stock either
dried up a long time ago or the repair people who will even touch these
things nowadays are probably clinging tenaciously to the reserve stocks
they do have (or want an arm and a leg for them).

thanks again to everyone who replied

Dave

Re-manufacturing pots to work in a semi-static application, such as a tone

control, is one thing. I still think that doing the same for a pot that is
going to get 'used', as just about every pot on a synthesiser *is*, due to
the very nature of the beast, is going to be beyond doing reliably by
amateur kitchen-table chemistry ... Just my opinion ...

Arfa

 

[JeffM]

David Forsyth TOP-POSTED:

I just never know when I can get online
and sometimes the older messages dont show up in my listings.

Note 1:
If something from previous posts
is not worthy of being ABOVE your post,
it should be eliminated entirely from your post.
It's called **trim and bottom-post**.

Note 2:
Excellent capture and retention here:
http://groups.google.com/group/sci.electronics.components/browse_frm/thread/9e5865a448fa2327/58fb854b042b223b

 

[Chris Jones]

David Forsyth wrote:

I have a need to rebuild some slide pots from 1970's musical equipment
that
have worn-through resistance strips. The pots are long since unobtainable
(made by CTS), and I have yet to find any suitable replacements. The
resistance strips inside the pots are removable, and consist of a die-cut
non-conductive substrate onto which a carbon resistance compound was bound
and on which the slide contact of the pot slides. Each end of the strip
has a metal connnector crimped to it to serve as an end terminal for the
pot.

I think if I knew what kind of binder and process is commonly used to
adhere
the carbon to the substrate I could restore the resistance layer. It
would
most likely have to be baked onto the strip, which is not a problem. For
the resistance material itself, I was thinking of using material from
carbon comp resistors (it would be trial and error to find the right value
for this
application). So, I am trying to find information on how resistance
material is bound to a substrate for use in wiper/pot applications (it
would
have to be fairly resistant to abrasion, solvents, etc.) Please email
foda01 at epix dot net with any helpful info.

thanks,

Dave

If these instruments are to be sold to the public then I agree with the
others that you probably should make an obtainable pot fit and adapt the
mechanical parts and circuit as necessary, because home-made pots will
quite likely wear out quickly and your customers may not feel like they had
their money's worth.

If you do feel like making your own pots anyway, I wonder whether you might
find that black conductive ESD-safe bags are suitable, at least for
short-term use. In the UK at least, Farnell sells chips packed in black
bags which I think are made by Vermason and are marked PE-LD. In my
experiments I have found that if you cut a strip from one side of the bag,
the strip of plastic seems to be made of three layers stuck together. Each
surface of the strip is conductive but both conductive layers are insulated
from each other.
http://www.vermason.co.uk/products/packaging/conductive_flexpack.asp
If the resistivity is right then you might be able to glue a layer into your
pots. It is probably not easy to glue it in a permanent way. So basically
the material is conductive on both sides but if you wiper is on the top
surface then the end contacts need to be on the top surface also.

Making pots with a taper slightly different from linear should be easy
enough provided you can fit a strip of plastic which has a width that is
not uniform along the track.

Chris

 

[Homer J Simpson]

I am a private individual posting this irrelevant message

From Google.


--
..

--
..
..
..
..
..
..
..
..

--

 

[JW]

On 20 Feb 2007 18:32:36 -0800 "TONY_GAL" <from_tl@myway.com> wrote in
Message id: <1172025156.115978.317560@j27g2000cwj.googlegroups.com>:

A new European Chemical Testing Policy called
REACH has now been finalised by the European
Union. Under these proposals Chemicals of every
kind - from those used in industrial processes to the
ingredients of consumer products - will be tested on
Millions of animals from mice to fish to dogs, causing
untold suffering.

Can we eat them when they're finished with them?

MMmmmm mice....

 

[Franc Zabkar]

On Wed, 21 Feb 2007 06:24:53 -0500, JW <none@dev.nul> put finger to
keyboard and composed:

On 20 Feb 2007 18:32:36 -0800 "TONY_GAL" <from_tl@myway.com> wrote in
Message id: <1172025156.115978.317560@j27g2000cwj.googlegroups.com>:

A new European Chemical Testing Policy called
REACH has now been finalised by the European
Union. Under these proposals Chemicals of every
kind - from those used in industrial processes to the
ingredients of consumer products - will be tested on
Millions of animals from mice to fish to dogs, causing
untold suffering.

Can we eat them when they're finished with them?

MMmmmm mice....

I refuse to buy pet shampoos that have been tested on animals.

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

 

[j]

Note: I'm trying to cross-post this to sci.electronics.repair, hope
it works. If not, I'll try to post the info that's there, over to
here.

Here's the physical description:

It's about 1/4" in diameter and 1/8" thick. The 2 leads are about
1/4" apart. The color is black with white charactors, which I next
describe. It has a triangle laying on it's base (ie, pointing up).
The corners of the triangle appear to have some detail, perhaps
looking like arrowheads. I suspect it's the manufacturers logo which
I think I've seen before, but I don't know which manufacturer. Below
the triangle are the charactors "K271" and below that "99".

 

[j]

Looking thru this site, the logo looks like it's Matsushita/Panasonic.

http://www.dialelec.com/semiconductorlogos.html

 

[Ken Layton]

On Feb 25, 7:56 pm, "coolguy17111987" <coolguy17111...@gmail.com>
wrote:

Now you can call anywhere in world for free

Nothing to see here.

 

WHAT IS ISLAM? Intolerance

 

[Radiosrfun]

<tnom@mucks.net> wrote in message
news:sla5u25r2fd42f143q80fdnbf9hu3tdn9l@4ax.com...

WHAT IS ISLAM? Intolerance

A religion that Hitler himself would have loved. THAT IS ALL it is - desire
to rule over all.


To the OP of this IS LAME shit

STUFF ISLAM UP YOUR ASS. Or come here - yellow belly, I'll do it for you.
Not a one of you pricks are man enough for hand to hand combat.

 

[Radiosrfun]

"Radiosrfun" <Radiosrfun@radiosrfun.com> wrote in message
news:45e2eb27$0$6834$ecde5a14@news.coretel.net...

tnom@mucks.net> wrote in message
news:sla5u25r2fd42f143q80fdnbf9hu3tdn9l@4ax.com...
WHAT IS ISLAM? Intolerance

A religion that Hitler himself would have loved. THAT IS ALL it is -
desire to rule over all.


To the OP of this IS LAME shit

STUFF ISLAM UP YOUR ASS. Or come here - yellow belly, I'll do it for you.
Not a one of you pricks are man enough for hand to hand combat.

SHIT - I made a typo - they can't stuff Islam up their ass, their buddies
dick or tongue is already there - the queer bastards.

My bad!