Toshiba TV29C90 problem; Image fades to black...

On Tue, 09 Jan 2007 11:04:46 -0500, Meat Plow <meat@meatplow.local>
wrote:

On Tue, 09 Jan 2007 15:29:42 +0000, jtaylor Has Frothed:

Broke the one in a gadget; need a source for a repair part.

http://www.horizontechnology.com/lcd_search.php

Yeah, thanks; was already there.

"Horizon Technology is a volume based business-to-business
distributor. We do not sell to consumers. "

Quantity One, please.

 

[Michael A. Terrell]

jtaylor@NOSPAM.hfx.andara.com wrote:

On Tue, 09 Jan 2007 11:04:46 -0500, Meat Plow <meat@meatplow.local
wrote:

On Tue, 09 Jan 2007 15:29:42 +0000, jtaylor Has Frothed:

Broke the one in a gadget; need a source for a repair part.

http://www.horizontechnology.com/lcd_search.php

Yeah, thanks; was already there.

"Horizon Technology is a volume based business-to-business
distributor. We do not sell to consumers. "

Quantity One, please.

Have you asked them to put you in contact with a customer who does
buy large quantities?


--
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

 

On Mon, 8 Jan 2007 10:36:51 -0500, "Zachary Burns"
<zacharyburns@shotmail.com> wrote:

I've got what I think to be a Carbon Resistor (brown cylindrical case with
no bubbled out ends) with 5 bands on it.

Band 1 = Orange
Band 2 = White
Band 3 = Green
Band 4 = Silver
Band 5 = Green

I think this comes out to be 3.95 Ohms (10% Tollerance) Right?

New to this stuff and want to make sure I order the right part.

Zack

I think you have a capacitor, not a resister. Band 5 is

a characteristic code, either temperature coefficient or
capacitance drift.

In your case .039 micro farads at 0 to +70 (ppm/Centigrade)
or plus or minus .05% + 0.1 pF

 

[David Farber]

"David Farber" <farberbear.unspam@aol.com> wrote in message
news:enua68$n9b$1@aioe.org...


"David Farber" <farberbear.unspam@aol.com> wrote in message
news:enmdu4$e8m$1@aioe.org...
This 17" Dell monitor, model number CN-0M1609-4633-3AG-2DTL, will
power
on
when AC is first applied. In the middle of the screen appears, "Dell
Genesis
Display Perfection." Then it disappears after a second. When you
press
the
power button with no input signal, the Dell self test feature check
illuminates in the bottom left corner of the display. You can see the
red,
green, blue, and white bars within the self test box. Then, it starts
to
scroll diagonally up to the right for about a second and then the
display
turns off. The power light remains on. If you hook it up to a PC, you
do
not
get any display. The boards are in good condition and I reflowed the
solder
over many of the components with no improvement. Any ideas what might
be
going on here?

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA




grobinso@lycos.co.uk> wrote in message
news:I0xoh.22673$RL5.14448@newsfe2-gui.ntli.net...

Hi David

I bought aDell E172fp off Ebay recently which was sold as faulty, the
Power
Light would flash on/off with no display.

Basically, what i have found is that the output transistors go s/c,
these
are the small 2sc5707 transistors that sit near the 4 yellow
transformers.
i
had 2 go s/c in one of the channels, the other channel was ok. I
replaced
these and now the green light stays on , the display comes on for about
3
seconds like you's does and then goes off.

I put a scope on the o/p of the transformers and can see them switching
ok
for 3 secs then the o/p goes off. What is happening is that the Pulse
Width
Modulator chip that drives the lamps is shutting down after 3 seconds,
this
is the 16 pin chip marked TL1451A. I have the datasheet on this chip
and
i
am currently trying to work out why it shuts down. I have found that
whe
you first switch on the monitor, the supply to this chip is 18vdc, when
the
display comes on for 3 seconds this drops to 14 volts (because this
supply
is unregulated) and then goes back to 18vdc.

I would be interested to know if you can confirm the dc voltage you are
seeing on pin 9 the 16 pin TL1451A chip during this startup period
and
see if it compares to my results.

Theres a common problem here with these monitors, it may be overcurrent
due
to s/c transformers or another transistor s/c somewhere, i am sure we
will
track it down shortly.

Graham


Hi Graham,

I checked those 2SC5707 transistors again. This time I found two of
them,
Q759 and Q760, were shorted b-e. I'll order those parts, replace them,
and
let you know what happens.

Thanks for your reply.

--
David Farber
David Farber's Service Center
L.A., CA

<grobinso@lycos.co.uk> wrote in message
news:9syoh.13411$696.1764@newsfe7-win.ntli.net...

David, ok, i havent been able to get any of them over here but i have used
BD911 as test devices.

If you get a minute would be interested to know what voltage you have on
pin9 of the PWM chip as i mentioned in my last post.

Graham

Graham,

Is it ok that the bad transistors are removed when I check the voltages? I
haven't received the replacements yet.

--
David Farber
David Farber's Service Center
L.A., CA

 

Hi David, i believe it should be ok with the trannies out, it just means
that one channel will not be driven.

Would be interested to know if you still have the same symptom (on for 2-3
secs and then off) with the trannies out.

I think what is happening is that the PWM chip is detecting overcurrent and
shutting down. I found that with BD911 transistors in in place of the
2sc5707 i am still getting the same problem but i cant find any more s/c
devices. As i understand it , with these monitors this is a real common
problem, even if you manage to get the thing working its likely to break
down again, with the same devices s/c a day/week/or even months later. It
seems its always the same channel (the top lamp) that goes but no-one really
knows why. I also understand that the transformers are suspect and go s/c or
arc internally. Dry solder joints are also a major problem as are poor
quality electrolytic caps.

I am coming to the conclusion that this monitor suffers from a major design
fault from new, they seem to just make it out of warranty and then fail

Apparently many service shops now refuse to handle them, they are a warranty
claim waiting to happen.

I am going to continue working on it though as i hate to give up on things
like this, its my own monitor so cost isnt an issue but for repair shops it
well cold be.

Anyway, let me know what you find with the voltages, should be interesting.

Regards

Graham
"David Farber" <farberbear.unspam@aol.com> wrote in message
news:enmdu4$e8m$1@aioe.org...

This 17" Dell monitor, model number CN-0M1609-4633-3AG-2DTL, will power
on
when AC is first applied. In the middle of the screen appears, "Dell
Genesis
Display Perfection." Then it disappears after a second. When you press the
power button with no input signal, the Dell self test feature check
illuminates in the bottom left corner of the display. You can see the red,
green, blue, and white bars within the self test box. Then, it starts to
scroll diagonally up to the right for about a second and then the display
turns off. The power light remains on. If you hook it up to a PC, you do
not
get any display. The boards are in good condition and I reflowed the
solder
over many of the components with no improvement. Any ideas what might be
going on here?

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA

 

[David Farber]

"David Farber" <farberbear.unspam@aol.com> wrote in message
news:enmdu4$e8m$1@aioe.org...
This 17" Dell monitor, model number CN-0M1609-4633-3AG-2DTL, will power
on
when AC is first applied. In the middle of the screen appears, "Dell
Genesis
Display Perfection." Then it disappears after a second. When you press
the
power button with no input signal, the Dell self test feature check
illuminates in the bottom left corner of the display. You can see the
red,
green, blue, and white bars within the self test box. Then, it starts to
scroll diagonally up to the right for about a second and then the
display
turns off. The power light remains on. If you hook it up to a PC, you do
not
get any display. The boards are in good condition and I reflowed the
solder
over many of the components with no improvement. Any ideas what might be
going on here?

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA

<grobinso@lycos.co.uk> wrote in message
news:txUoh.61045$n36.43746@newsfe7-gui.ntli.net...

Hi David, i believe it should be ok with the trannies out, it just means
that one channel will not be driven.

Would be interested to know if you still have the same symptom (on for
2-3
secs and then off) with the trannies out.

I think what is happening is that the PWM chip is detecting overcurrent
and
shutting down. I found that with BD911 transistors in in place of the
2sc5707 i am still getting the same problem but i cant find any more s/c
devices. As i understand it , with these monitors this is a real common
problem, even if you manage to get the thing working its likely to break
down again, with the same devices s/c a day/week/or even months later. It
seems its always the same channel (the top lamp) that goes but no-one
really
knows why. I also understand that the transformers are suspect and go s/c
or
arc internally. Dry solder joints are also a major problem as are poor
quality electrolytic caps.

I am coming to the conclusion that this monitor suffers from a major
design
fault from new, they seem to just make it out of warranty and then fail


Apparently many service shops now refuse to handle them, they are a
warranty
claim waiting to happen.

I am going to continue working on it though as i hate to give up on things
like this, its my own monitor so cost isnt an issue but for repair shops
it
well cold be.

Anyway, let me know what you find with the voltages, should be
interesting.

Regards

Graham

Hi Graham,

I checked the voltage at pin 9 of the TL1451A chip and have come up with the
same results that you found in your monitor. The voltage swings from 14 to
18 volts after shutdown.
--
David Farber
David Farber's Service Center
L.A., CA

 

[Arfa Daily]

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

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:8YBoh.23419$RL5.14506@newsfe2-gui.ntli.net...

"N Cook" <diverse8@gazeta.pl> wrote in message
news:enu9fm$jhr$1@inews.gazeta.pl...
Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:Uhwoh.47370$Qa6.7736@newsfe6-gui.ntli.net...

"N Cook" <diverse8@gazeta.pl> wrote in message
news:ento64$1p6$1@inews.gazeta.pl...
Ten years ago I would have considered it impractical or even
immoral.
But having to replace yet another effectively all plastic 12 mm pot
because
the wiper is almost invisible in thickness, perhaps time for a
rethink.
This type of pot has a metal covering but its only function is as a
shroud
for fixing to the board, not even earthed, it does not strengthen
the
pot
body to restrain abuse at the other, user end. No longer are such
pots
fixed
to the front pannel.
I'm thinking that with the next one to replace it will be with a
standard
small 12 mm or so enclosed preset that takes a standard plastic
shaft
in
the
adjustment slot, fudging the other end of the shaft to take the knob
and
through pannel bearer. The internal mechanism is just a pro-rata
scaled
down
conventional paxolin backed track with double wiper nibs.
If this replacement physically breaks in use then that seems more
justifiable than the modern flimsy wipers losing spring action or
just
aging
of the lubricant inside to wedge under the wiper and loose contact
or
whatever their problem is, the tracks are always perfect (so little
wiper
pressure presumably).
Are the resistive tracks of presets more frail/easier scoored than
pot
tracks, so for that reason cannot be used say for volume control ?
Anyone any opinions?

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


I would have said that the description " preset " tells you all that
you
need to know on that score. These components are designed to be set
and
left, pretty much for the lifetime of the equipment, so I can't see
them
standing up to the rigours of regular use for long. Add to this that
as
they
are not designed to be rotated repeatedly as a user control, the wiper
/
track interface has not been designed to be specifically quiet. I also
think
that the control will feel bad to a user, as it will not have that "
stirring treacle " feel that a proper user control has, courtesy of
the
drag
grease that the manufacturers put in the spindle bush. Why not replace
controls with manufacturer's originals ? Most group amp builders
supply
spare parts. Failing that, there are plenty of reasonable quality pots
available - even the range that Maplin keep are pretty fair quality -
and
if
you really want to fit top quality pots, these are also available from
audiophile outlets.

Arfa



I had not considered the feel, which agreed is very 'scratchy'.
Squirting silicone oil in one and turning back and forth a hundred
times
is
very much improved, and resistive track still ok.
What is the point of the feather-light touch of the flimsy pots if the
downside is they just don't last.
I don't see the point of replacing with an exact match when the
original
is
say one of 8 and has only lasted for use once a week for 2 years before
internally failing , ie not abuse. In fact they seem to be the pots
that
are
not used much if at all, that's why I suspect clumping or something in
the
lubricant.
I'll try a 1000 times and re-measure to see if the track fails.

--

I'm actually really surprised that you seem to come across so many bad
pots
in group amps. I have been repairing these for many many years, and do
lots
of all makes and models, for a local shop, and I really don't have to
replace many pots that aren't physically broken through taking knocks. I
have found in general, that most manufacturers appreciate that this gear
is
going to last its owners for a lot of years, and tailor their design
criteria, and component spec-ing to suit. I would agree that the pots
fitted
these days tend to be Japanese ( probably Chinese actually ) small-bodied
types, which are not as good quality as say the large body Wellyns or the
typical RS components pots that you used to find in them a few years
back,
but still, I don't seem to have that much trouble with them. If you
really
think that the problem is insufficient spring tension on the wiper
fingers,
just pile a bit more on. It's easily done with a pair of long-nosed
pointy
surgical tweezers.

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






The present problematic is a Carvin Pro Bass 100, PB100 which will come
bouncing back next weekend.
The new fault , could well be due to another pot failed, symptoms over the
phone so far, the previous one I replaced is fine.
I still have the previous original one lying around .
No makers name , a logo like cross-section of a flying saucer, a thin
elipse
laid over a circle, just the outermost lineforms.
The wiper is only 0.15 mm thick , 0.6mm wide and using a force gauge, it
starts deflecting at only 12 grams pressure.

Followup on my endurance test on a preset, I survived 1000 turns back and
forth , whole track, as did the pot. No wavering on mid-track resistance
readings. The rough feel has returned but I doubt that is due to the wiper
action. Cracking it open, one obvious shiny, but not broken through to
paxolin, track from one nib and vague partial thin trace from the other
nib.
I would estimate it could have done more than 10,000 rotations before both
tracks were worn through.


In that case, go for it. I would be interested to know how you get on with

such transpants, and which presets you ultimately find most suitable. Also,
how quiet they are in actual practical usage.

Arfa

 

[Paul]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:wowoh.54943$HV6.19148@newsfe1-gui.ntli.net...

"Morse" <morse@rpa.com> wrote in message
news:0NydnUhq8fNF_j_YnZ2dnUVZ8q6nnZ2d@pipex.net...

"Paul" <satellite65@yahoo.com> wrote in message
news:1168266070.855263.251610@42g2000cwt.googlegroups.com...
I was having trouble with CDs skipping on the factory radio in my 94
Trans Am..... How can I determine the polarity of the capacitors?
The
level of disassembly needed to get at these parts does not lend itself
to powering the unit up and measuring voltage accross the cap's.

At least some if not all of those caps should have the negative leads at
ground potential, so use your multimeter on Ohms or continuity setting
and find out which lead is negative that way, no need to power the unit
up. Or simply visually trace the cap lead to the ground plane on the PCB.

Morse


What do you consider to be a "high" value for ESR on these caps ? 4u7 at
6.3v will likely have a correct ESR value of 15 ohms or more. You should
also be careful when replacing small electrolytics like this, that you
only replace with exact like for like. On many Sony HiFi CD players from a
few years ago, the CD servo board had several small caps of very similar
description to the ones you have there. One in particular used to leak. If
you tried to replace these caps with anything other than the original low
voltage surface mount types, the servos would never work again.

Arfa

The ESR measures 50 ohms on my meter.
Typically fresh 4.7uF caps measure about 2 ohms on my meter.

Thanks for the warning that generic replacements might cause trouble.
So far, no luck finding original type replacements from Mouser, etc.
Don't suppose you can point me to a source???

Paul

 

Thanks David, will be interesting to see what happens after you get the
replacement transistors in. Perhaps my continuing problems are due to having
tried BD911 transistors in place of the 2sc5707.

Let me know how you get on please.

Graham


"David Farber" <farberbear.unspam@aol.com> wrote in message
news:12q87m840j8scdb@corp.supernews.com...

"David Farber" <farberbear.unspam@aol.com> wrote in message
news:enmdu4$e8m$1@aioe.org...
This 17" Dell monitor, model number CN-0M1609-4633-3AG-2DTL, will
power
on
when AC is first applied. In the middle of the screen appears, "Dell
Genesis
Display Perfection." Then it disappears after a second. When you press
the
power button with no input signal, the Dell self test feature check
illuminates in the bottom left corner of the display. You can see the
red,
green, blue, and white bars within the self test box. Then, it starts
to
scroll diagonally up to the right for about a second and then the
display
turns off. The power light remains on. If you hook it up to a PC, you
do
not
get any display. The boards are in good condition and I reflowed the
solder
over many of the components with no improvement. Any ideas what might
be
going on here?

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA





grobinso@lycos.co.uk> wrote in message
news:txUoh.61045$n36.43746@newsfe7-gui.ntli.net...
Hi David, i believe it should be ok with the trannies out, it just means
that one channel will not be driven.

Would be interested to know if you still have the same symptom (on for
2-3
secs and then off) with the trannies out.

I think what is happening is that the PWM chip is detecting overcurrent
and
shutting down. I found that with BD911 transistors in in place of the
2sc5707 i am still getting the same problem but i cant find any more s/c
devices. As i understand it , with these monitors this is a real common
problem, even if you manage to get the thing working its likely to break
down again, with the same devices s/c a day/week/or even months later. It
seems its always the same channel (the top lamp) that goes but no-one
really
knows why. I also understand that the transformers are suspect and go s/c
or
arc internally. Dry solder joints are also a major problem as are poor
quality electrolytic caps.

I am coming to the conclusion that this monitor suffers from a major
design
fault from new, they seem to just make it out of warranty and then fail


Apparently many service shops now refuse to handle them, they are a
warranty
claim waiting to happen.

I am going to continue working on it though as i hate to give up on
things
like this, its my own monitor so cost isnt an issue but for repair shops
it
well cold be.

Anyway, let me know what you find with the voltages, should be
interesting.

Regards

Graham

Hi Graham,

I checked the voltage at pin 9 of the TL1451A chip and have come up with
the
same results that you found in your monitor. The voltage swings from 14 to
18 volts after shutdown.
--
David Farber
David Farber's Service Center
L.A., CA

 

[Ron(UK)]

Arfa Daily wrote:

In that case, go for it. I would be interested to know how you get on with
such transpants, and which presets you ultimately find most suitable. Also,
how quiet they are in actual practical usage.

Arfa

I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Ron(UK)

 

[Arfa Daily]

"Ron(UK)" <ron@lunevalleyaudio.com> wrote in message
news:GsGdnU8sWejcLTnYRVnytwA@bt.com...

Arfa Daily wrote:


In that case, go for it. I would be interested to know how you get on
with such transpants, and which presets you ultimately find most
suitable. Also, how quiet they are in actual practical usage.

Arfa

I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Ron(UK)

Hi Ron. That is a very good point, and one that I hadn't even considered
when thinking about his original plan to use these. If you look in the post
that started the thread, he says that he is intending using the presets that
you can get a 6mm shaft for that turns them into a ( semi ?? ) user
control - I'm sure you've seen the idea on stuff where there is an
adjustment that would be a good idea to have available to the user, but not
in a way that encourages him to *use* it. The shafts that I've seen usually
have a lightly splined finish so that they can be gripped, and a screwdriver
slot in the end. I think he intends to pass one of these through a panel
mount shaft bush, and then persuade the knob to fit.

Arfa

 

[N Cook]

Ron(UK) <ron@lunevalleyaudio.com> wrote in message
news:GsGdnU8sWejcLTnYRVnytwA@bt.com...

Arfa Daily wrote:


In that case, go for it. I would be interested to know how you get on
with
such transpants, and which presets you ultimately find most suitable.
Also,
how quiet they are in actual practical usage.

Arfa


I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Ron(UK)

I should have said the failed original in the 0.6mm was 2 wipers , the metal
is split into 2 wipers and nibs, absolutely no trace of wear on the track.

I have a few hundred Piher presets that have an enlarged slot to take rod
extenders with pair of pauls to engage the back of the slot, quite strong
enough to be used as unabused pots.
The very light action of the originals I would have thought were a
disadvantage, on stage, as you could easily dislodge a neighbouring pot.
Some of these Piher presets are log tracks, agreed unusual but useful

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

 

[Arfa Daily]

"Paul" <satellite65deletethis@yahoo.com> wrote in message
news:12q8ou05802cv58@corp.supernews.com...

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:wowoh.54943$HV6.19148@newsfe1-gui.ntli.net...

"Morse" <morse@rpa.com> wrote in message
news:0NydnUhq8fNF_j_YnZ2dnUVZ8q6nnZ2d@pipex.net...

"Paul" <satellite65@yahoo.com> wrote in message
news:1168266070.855263.251610@42g2000cwt.googlegroups.com...
I was having trouble with CDs skipping on the factory radio in my 94
Trans Am..... How can I determine the polarity of the capacitors?
The
level of disassembly needed to get at these parts does not lend itself
to powering the unit up and measuring voltage accross the cap's.

At least some if not all of those caps should have the negative leads at
ground potential, so use your multimeter on Ohms or continuity setting
and find out which lead is negative that way, no need to power the unit
up. Or simply visually trace the cap lead to the ground plane on the
PCB.

Morse


What do you consider to be a "high" value for ESR on these caps ? 4u7 at
6.3v will likely have a correct ESR value of 15 ohms or more. You should
also be careful when replacing small electrolytics like this, that you
only replace with exact like for like. On many Sony HiFi CD players from
a few years ago, the CD servo board had several small caps of very
similar description to the ones you have there. One in particular used to
leak. If you tried to replace these caps with anything other than the
original low voltage surface mount types, the servos would never work
again.

Arfa

The ESR measures 50 ohms on my meter.
Typically fresh 4.7uF caps measure about 2 ohms on my meter.

Thanks for the warning that generic replacements might cause trouble.
So far, no luck finding original type replacements from Mouser, etc.
Don't suppose you can point me to a source???

Paul
Hi Paul. Agreed that a *standard* electrolytic of that value will read a
couple of ohms, but I've found that these very low voltage ones on the SM
bases tend to read much higher than that, even when new, although I think I
would, like you, consider 50 ohms to be too high. Just something to be
aware of for the future. As far as where to get them, I'm afraid I'm the
opposite side of the pond here, so not much help on that score, except to
say that I don't have any problem getting low voltage SM electrolytics
here, allbeit with a slightly larger footprint than the ones Sony
originally fit. I'm sure there must be others on here that can help with
that.

Arfa

 

[Ron(UK)]

Arfa Daily wrote:

"Ron(UK)" <ron@lunevalleyaudio.com> wrote in message
news:GsGdnU8sWejcLTnYRVnytwA@bt.com...
Arfa Daily wrote:

In that case, go for it. I would be interested to know how you get on
with such transpants, and which presets you ultimately find most
suitable. Also, how quiet they are in actual practical usage.

Arfa
I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Ron(UK)

Hi Ron. That is a very good point, and one that I hadn't even considered
when thinking about his original plan to use these. If you look in the post
that started the thread, he says that he is intending using the presets that
you can get a 6mm shaft for that turns them into a ( semi ?? ) user
control - I'm sure you've seen the idea on stuff where there is an
adjustment that would be a good idea to have available to the user, but not
in a way that encourages him to *use* it. The shafts that I've seen usually
have a lightly splined finish so that they can be gripped, and a screwdriver
slot in the end. I think he intends to pass one of these through a panel
mount shaft bush, and then persuade the knob to fit.

Arfa

Ah ok, Piher do a range of shafts for their min presets. I`ve used them
on radio mike receivers etc. to replace the output level and squelch
controls, invariably because the user has been heavy handed with them.
The combined cost of preset and shaft is quite high compared with a
normal pot.

Personally I like the Omeg ECO plastic pots for replacements on gear
that takes standard quarter inch bore knobs, Rapid Electronics stock
the pots with the monkey metal slotted and splined short shaft that fits
a lot of the Chinese product

Ron(UK)

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

 

[Eeyore]

"Ron(UK)" wrote:

Arfa Daily wrote:

In that case, go for it. I would be interested to know how you get on with
such transpants, and which presets you ultimately find most suitable. Also,
how quiet they are in actual practical usage.

I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Never IME.

Graham

 

[N Cook]

Ron(UK) <ron@lunevalleyaudio.com> wrote in message
news:aNmdnZxcXcDCJDnYnZ2dnUVZ8sKlnZ2d@bt.com...

Arfa Daily wrote:
"Ron(UK)" <ron@lunevalleyaudio.com> wrote in message
news:GsGdnU8sWejcLTnYRVnytwA@bt.com...
Arfa Daily wrote:

In that case, go for it. I would be interested to know how you get on
with such transpants, and which presets you ultimately find most
suitable. Also, how quiet they are in actual practical usage.

Arfa
I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Ron(UK)

Hi Ron. That is a very good point, and one that I hadn't even considered
when thinking about his original plan to use these. If you look in the
post
that started the thread, he says that he is intending using the presets
that
you can get a 6mm shaft for that turns them into a ( semi ?? ) user
control - I'm sure you've seen the idea on stuff where there is an
adjustment that would be a good idea to have available to the user, but
not
in a way that encourages him to *use* it. The shafts that I've seen
usually
have a lightly splined finish so that they can be gripped, and a
screwdriver
slot in the end. I think he intends to pass one of these through a panel
mount shaft bush, and then persuade the knob to fit.

Arfa




Ah ok, Piher do a range of shafts for their min presets. I`ve used them
on radio mike receivers etc. to replace the output level and squelch
controls, invariably because the user has been heavy handed with them.
The combined cost of preset and shaft is quite high compared with a
normal pot.

Personally I like the Omeg ECO plastic pots for replacements on gear
that takes standard quarter inch bore knobs, Rapid Electronics stock
the pots with the monkey metal slotted and splined short shaft that fits
a lot of the Chinese product

Ron(UK)

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

If you mean the Vishay 12/13mm footprint pots then they are the right size
but the manufacturer's pdfs don't give the wiper dimensions , if of
thickness of a coarse human hair , 150 microns, then little point in using,
as will be back to square 1 in a few years.

 

[Zachary Burns]

Is there a way to tell for sure?

If I took a picture could you tell?

Some cable technician cut this off of my friends television (she said it
stopped working on New Year's - must have been some party), anyway, and the
cable tv tech said it was bad. I told her the cable technician is probably
smoking crack! The component (looks like a resistor to me) isn't bad from
the limited testing I did, but I need to order a new one for her.

I'm a computer guy just trying to help her out....not an electrical
engineer.

Zack



<tnom@mucks.net> wrote in message
news:bgu7q2d528jtit1nl6lof4n6ttq2goigrd@4ax.com...

On Mon, 8 Jan 2007 10:36:51 -0500, "Zachary Burns"
zacharyburns@shotmail.com> wrote:

I've got what I think to be a Carbon Resistor (brown cylindrical case with
no bubbled out ends) with 5 bands on it.

Band 1 = Orange
Band 2 = White
Band 3 = Green
Band 4 = Silver
Band 5 = Green

I think this comes out to be 3.95 Ohms (10% Tollerance) Right?

New to this stuff and want to make sure I order the right part.

Zack

I think you have a capacitor, not a resister. Band 5 is
a characteristic code, either temperature coefficient or
capacitance drift.

In your case .039 micro farads at 0 to +70 (ppm/Centigrade)
or plus or minus .05% + 0.1 pF

 

[Michael Black]

"Zachary Burns" (zacharyburns@shotmail.com) writes:

Is there a way to tell for sure?

If I took a picture could you tell?

Some cable technician cut this off of my friends television (she said it
stopped working on New Year's - must have been some party), anyway, and the
cable tv tech said it was bad. I told her the cable technician is probably
smoking crack! The component (looks like a resistor to me) isn't bad from
the limited testing I did, but I need to order a new one for her.

I'm a computer guy just trying to help her out....not an electrical
engineer.

Zack

This is why it's always important to give all the details to begin with.

Your original post suggested the part was bad, which ruled out the obvious
means of verifying the color code. That would be you take an ohmmeter
and measure it, and that would give you the basis to interpret the
color code. This is also useful in recent years when sometimes the
colors used to code the resistors are odd looking, so at a glance it's
not clear what standard color a band is supposed to be.

But given the assumption it was bad, then there the measured resistance
wouldn't match the color code.

If the resistance matches the expected value of the color code, then you
know it's good.

If the value is zero, or close to it (which might be hard to judge
given the color code indicates a quite low value resistor) then it is
likely bad, because a bad capacitor could be shorted.

An open circuit (ie really high resistance) sure wouldn't be what
the color code suggests it would be as a resistor, but it might
be a capacitor, since capacitors will be open (though high value
capacitors will charge up, showing a low value resistance at first
and a high value resistance in the end). A capacitance meter,
or the function on a DMM, would give an indication of whether the
value matches some color code scheme for capacitors.

But, you have a bigger problem, something that would have been
bypassed in the first place if you'd revealed the whole story. Your
original post was so sparse that people took the question literally
when the answers should have dealt with the bigger problem.

YOu have some guy who may not have been qualified to look at the
tv set, and then turns around and drops the problem in your lap, and
you aren't qualified either. It doesn't even sound like you know
exactly what the "cable technician" was doing.

Given all that, it's no wonder you are going to have problems here.
Because you aren't actually evaluating the tv set, you are trying
to fix something some other guy has decided is the problem, and
only he knows why he thinks that.

Drop it back in his lap, because he's the one who's done the damage
so far.

Michael

tnom@mucks.net> wrote in message
news:bgu7q2d528jtit1nl6lof4n6ttq2goigrd@4ax.com...
On Mon, 8 Jan 2007 10:36:51 -0500, "Zachary Burns"
zacharyburns@shotmail.com> wrote:

I've got what I think to be a Carbon Resistor (brown cylindrical case with
no bubbled out ends) with 5 bands on it.

Band 1 = Orange
Band 2 = White
Band 3 = Green
Band 4 = Silver
Band 5 = Green

I think this comes out to be 3.95 Ohms (10% Tollerance) Right?

New to this stuff and want to make sure I order the right part.

Zack

I think you have a capacitor, not a resister. Band 5 is
a characteristic code, either temperature coefficient or
capacitance drift.

In your case .039 micro farads at 0 to +70 (ppm/Centigrade)
or plus or minus .05% + 0.1 pF

 

[Homer J Simpson]

"Zachary Burns" <zacharyburns@shotmail.com> wrote in message
news:45a51501$0$91106$815e3792@news.qwest.net...

If I took a picture could you tell?

Post it in ABSE







--

 

[Ron(UK)]

N Cook wrote:

Ron(UK) <ron@lunevalleyaudio.com> wrote in message
news:aNmdnZxcXcDCJDnYnZ2dnUVZ8sKlnZ2d@bt.com...
Arfa Daily wrote:
"Ron(UK)" <ron@lunevalleyaudio.com> wrote in message
news:GsGdnU8sWejcLTnYRVnytwA@bt.com...
Arfa Daily wrote:

In that case, go for it. I would be interested to know how you get on
with such transpants, and which presets you ultimately find most
suitable. Also, how quiet they are in actual practical usage.

Arfa
I'm interested to know how the OP plans to reliably connect a standard
shaft to a preset, I`m presuming his idea of a preset and mine concur.

One other point, presents don`t normally come in log tapers, do they?

Ron(UK)
Hi Ron. That is a very good point, and one that I hadn't even considered
when thinking about his original plan to use these. If you look in the
post
that started the thread, he says that he is intending using the presets
that
you can get a 6mm shaft for that turns them into a ( semi ?? ) user
control - I'm sure you've seen the idea on stuff where there is an
adjustment that would be a good idea to have available to the user, but
not
in a way that encourages him to *use* it. The shafts that I've seen
usually
have a lightly splined finish so that they can be gripped, and a
screwdriver
slot in the end. I think he intends to pass one of these through a panel
mount shaft bush, and then persuade the knob to fit.

Arfa



Ah ok, Piher do a range of shafts for their min presets. I`ve used them
on radio mike receivers etc. to replace the output level and squelch
controls, invariably because the user has been heavy handed with them.
The combined cost of preset and shaft is quite high compared with a
normal pot.

Personally I like the Omeg ECO plastic pots for replacements on gear
that takes standard quarter inch bore knobs, Rapid Electronics stock
the pots with the monkey metal slotted and splined short shaft that fits
a lot of the Chinese product

Ron(UK)

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

If you mean the Vishay 12/13mm footprint pots then they are the right size
but the manufacturer's pdfs don't give the wiper dimensions , if of
thickness of a coarse human hair , 150 microns, then little point in using,
as will be back to square 1 in a few years.

I didn't, I meant Omeg, but the Vishay pots will certainly be better
than anything fitted as an original part by the vast majority of
manufacturers.

Ron(UK)

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com