sci.electronics.repair - 26 new messages in 8 topics - digest

sci.electronics.repair
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Today's topics:

==============================================================================
TOPIC: Repairing flexible pcb connector track?
http://groups.google.com/group/sci.electronics.repair/t/ae4dd2364002cc94?hl=en
==============================================================================

== 1 of 12 ==
Date: Thurs, Jul 29 2010 10:33 am
From: "William Sommerwerck"

> It happened several days ago so have got over the initial shock
> and annoyance with myself. I am not rushing in until feel right.

Good. That means you'll probably come up with the "least bad" solution.

== 2 of 12 ==
Date: Thurs, Jul 29 2010 10:37 am
From: "Ian P"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:bHh4o.61130$0e3.22364@hurricane...
>
>
> "Ian P" <elanman99@yahoo.com> wrote in message
> news:8bdgspFuetU1@mid.individual.net...
>> In the course of doing some modifications to a very expensive Sony 3 chip
>> HD camcorder I have accidentally cut through 3 tracks on the edge of a
>> mylar? flexible cable. On the good side the damage is very accessible but
>> the bad bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally
>> one would just replace the flex pcb but in practice that would involve
>> dismantling the camera and lens to get to all the places the pcb branches
>> out to, and in some places it actually goes into the lens mechanism
>> itself.
>>
>> I am considering abrading off the top mylar coating to expose the copper
>> then bridging the breaks with some very narrow pitch zebra strip. My
>> other idea is to make my own miniature insulation displacement/piercing
>> connector using a stack of razor blade bits sandwiched with insulation
>> layers.
>>
>> The last option would be to use wire links and solder but I think this
>> could only be done with some sort of mechanical micropositioning rig in
>> view of the small sizes involved.
>>
>> I would be interested to hear any thoughts or experiences if anyone has
>> any.
>>
>> Cheers
>>
>>
>>
>> Ian
>>
>>
>
> Based on my experience of trying to repair accidental damage to
> flexiprints (yes, it happens to us all no matter how long we've been in
> the game and how experienced we are !) I think that you are going to
> struggle to get a fix on one of that tiny pitch. I have had plenty of
> success with abrading and soldering ones of a slightly greater pitch,
> doing it with a tiny needle-point soldering tip and under a microscope,
> and using a single strand from superflex instrument cable, such as is used
> for better quality meter leads, for instance.
>
> I don't know whether this is a commercial job, or one for a friend, or
> maybe even for yourself, but before you commit to any strategy that's
> going to waste a lot of time, and end up with no fix at the end of it
> anyway, the job would probably stand being left for a day or two, before
> revisiting it with a clear head, to look at how hard replacing the
> flexiprint would *really* be. I've often found that things that look as
> though they are going to be a copper-bottomed-gold-plated bitch to do, are
> actually not so bad, when looked at again after you've calmed down, and
> forced a degree of 'san fairy ann' into your head over it. If you have a
> copy of the service manual or can obtain one, a look at the parts list
> will tell you if replacement is even an option (if you're really unlucky
> it might be an integral part of the lens assembly) and if it is available,
> a look at the exploded view diagram, would be helpful to determine how
> many 'hidden' branches the flexiprint has, and where they go.
>
> I really feel for you on this one. I've been there many times over the
> years ...
>
> Good luck with it, and please post back, and let us know how you get on
> with it :-\
>
> Arfa

Arfa

Thanks for your advice. As you postulated this pcb is integral with the lens
and although I have the full service manual for the camera it give no
information at all on the lens which is a bought in item (not removable
though). The job is not really commercial, for a friend or myself but it a
sort of combination of all three. I caused the damage though and I need to
repair it because there is not really any alternative.

I have in the past repaired and modified boards and components and used thin
wire just as you described, this cable though has track and spacing widths
that are really challenging, and I don't have any microscope.

I have lots of old bits of similar flexible boards and cables so I am going
to experiment with them.

Ian

== 3 of 12 ==
Date: Thurs, Jul 29 2010 10:42 am
From: "William Sommerwerck"

> Thanks for your advice. As you postulated this pcb is integral with the
> lens and although I have the full service manual for the camera it give no
> information at all on the lens which is a bought in item (not removable
> though). The job is not really commercial, for a friend or myself but it a
> sort of combination of all three. I caused the damage though and I need
> to repair it because there is not really any alternative.

> I have in the past repaired and modified boards and components and used
> thin wire just as you described, this cable though has track and spacing
> widths that are really challenging, and I don't have any microscope.

> I have lots of old bits of similar flexible boards and cables so I am
going
> to experiment with them.

I'm starting to get the feeling that maybe you should "bite the bullet" and
have Sony do the repair. It's going to cost a lot of money, but it might be
worth it, simply in the grief saved.

== 4 of 12 ==
Date: Thurs, Jul 29 2010 11:00 am
From: "Paul Hovnanian P.E."

Ian P wrote:

> In the course of doing some modifications to a very expensive Sony 3 chip
> HD camcorder I have accidentally cut through 3 tracks on the edge of a
> mylar? flexible cable. On the good side the damage is very accessible but
> the bad bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally
> one would just replace the flex pcb but in practice that would involve
> dismantling the camera and lens to get to all the places the pcb branches
> out to, and in some places it actually goes into the lens mechanism
> itself.
>
> I am considering abrading off the top mylar coating to expose the copper
> then bridging the breaks with some very narrow pitch zebra strip. My other
> idea is to make my own miniature insulation displacement/piercing
> connector using a stack of razor blade bits sandwiched with insulation
> layers.
>
> The last option would be to use wire links and solder but I think this
> could only be done with some sort of mechanical micropositioning rig in
> view of the small sizes involved.
>
> I would be interested to hear any thoughts or experiences if anyone has
> any.

I've had some luck repairing individual breaks with a conductive repair pen.

Given the pitch you are working with, you might have to expose spots on each
trace that are separated by a few millimeters along the length of the
traces to prevent bridging them with the ink.

I'm not certain how well the conductive ink stands up to continued flexing.
Gluing some stiff backing behind the area of the repair might be a good
idea.

--
Paul Hovnanian paul@hovnanian.com
----------------------------------------------------------------------
Have gnu, will travel.

== 5 of 12 ==
Date: Thurs, Jul 29 2010 2:42 pm
From: "Ian P"

"Paul Hovnanian P.E." <paul@hovnanian.com> wrote in message
news:eemdnWmaANgfXMzRnZ2dnUVZ_tCdnZ2d@posted.isomediainc...
> Ian P wrote:
>
>> In the course of doing some modifications to a very expensive Sony 3 chip
>> HD camcorder I have accidentally cut through 3 tracks on the edge of a
>> mylar? flexible cable. On the good side the damage is very accessible but
>> the bad bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally
>> one would just replace the flex pcb but in practice that would involve
>> dismantling the camera and lens to get to all the places the pcb branches
>> out to, and in some places it actually goes into the lens mechanism
>> itself.
>>
>> I am considering abrading off the top mylar coating to expose the copper
>> then bridging the breaks with some very narrow pitch zebra strip. My
>> other
>> idea is to make my own miniature insulation displacement/piercing
>> connector using a stack of razor blade bits sandwiched with insulation
>> layers.
>>
>> The last option would be to use wire links and solder but I think this
>> could only be done with some sort of mechanical micropositioning rig in
>> view of the small sizes involved.
>>
>> I would be interested to hear any thoughts or experiences if anyone has
>> any.
>
> I've had some luck repairing individual breaks with a conductive repair
> pen.
>
> Given the pitch you are working with, you might have to expose spots on
> each
> trace that are separated by a few millimeters along the length of the
> traces to prevent bridging them with the ink.
>
> I'm not certain how well the conductive ink stands up to continued
> flexing.
> Gluing some stiff backing behind the area of the repair might be a good
> idea.
>
> --
> Paul Hovnanian paul@hovnanian.com
> ----------------------------------------------------------------------
> Have gnu, will travel.

If I can repair the broken tracks I will locally stiffen the ribbon so that
it will not be subject to flexing anyway. Your idea of staggering the links
(which I might do with wire and soldering) means that I have a bit more room
to work with.

Ian

== 6 of 12 ==
Date: Thurs, Jul 29 2010 2:42 pm
From: Grant

On Thu, 29 Jul 2010 15:17:56 +0100, "Ian P" <elanman99@yahoo.com> wrote:

>In the course of doing some modifications to a very expensive Sony 3 chip HD
>camcorder I have accidentally cut through 3 tracks on the edge of a mylar?
>flexible cable. On the good side the damage is very accessible but the bad
>bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally one would
>just replace the flex pcb but in practice that would involve dismantling the
>camera and lens to get to all the places the pcb branches out to, and in
>some places it actually goes into the lens mechanism itself.
>
>I am considering abrading off the top mylar coating to expose the copper
>then bridging the breaks with some very narrow pitch zebra strip. My other
>idea is to make my own miniature insulation displacement/piercing connector
>using a stack of razor blade bits sandwiched with insulation layers.
>
>The last option would be to use wire links and solder but I think this could
>only be done with some sort of mechanical micropositioning rig in view of
>the small sizes involved.
>
>I would be interested to hear any thoughts or experiences if anyone has any.

I feel for you, it's a serious oops moment to recover from.

Contact Sony for an idea of cost of fix, so you can place importance
of fixing yourself in your mind? If you can afford the fix at least
there's a way out.

You've got stuff to practice with, but I can't see how you're going to
reliably connect to that fine pitch. Are there accessible places where
the cut tracks get wider? Do the cut tracks terminate to accessible
places where you can create another, separate cable to bridge the
breaks?

IOW, sidestep trying to repair the damage by creating an alternate
circuit.

Seems to me it's a cable replacement, but that could be sub-assembly
replacement if the flex also gets glued in place to some smaller parts.

Take it easy, it is not a rush job.

Grant.

== 7 of 12 ==
Date: Thurs, Jul 29 2010 2:44 pm
From: "Ian P"

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:i2seib$u4b$1@news.eternal-september.org...
>> Thanks for your advice. As you postulated this pcb is integral with the
>> lens and although I have the full service manual for the camera it give
>> no
>> information at all on the lens which is a bought in item (not removable
>> though). The job is not really commercial, for a friend or myself but it
>> a
>> sort of combination of all three. I caused the damage though and I need
>> to repair it because there is not really any alternative.
>
>> I have in the past repaired and modified boards and components and used
>> thin wire just as you described, this cable though has track and spacing
>> widths that are really challenging, and I don't have any microscope.
>
>> I have lots of old bits of similar flexible boards and cables so I am
> going
>> to experiment with them.
>
> I'm starting to get the feeling that maybe you should "bite the bullet"
> and
> have Sony do the repair. It's going to cost a lot of money, but it might
> be
> worth it, simply in the grief saved.
>
>

I am not sure that Sony would want to repair the camera now because I was in
the process of carrying out electromechanical modifications so its a bit non
standard.

Ian

== 8 of 12 ==
Date: Thurs, Jul 29 2010 2:52 pm
From: "Ian P"

"Grant" <omg@grrr.id.au> wrote in message
news:vvs356tu89pe9lidcr37ohdtdf9ofkfm7f@4ax.com...
> On Thu, 29 Jul 2010 15:17:56 +0100, "Ian P" <elanman99@yahoo.com> wrote:
>
>>In the course of doing some modifications to a very expensive Sony 3 chip
>>HD
>>camcorder I have accidentally cut through 3 tracks on the edge of a mylar?
>>flexible cable. On the good side the damage is very accessible but the bad
>>bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally one would
>>just replace the flex pcb but in practice that would involve dismantling
>>the
>>camera and lens to get to all the places the pcb branches out to, and in
>>some places it actually goes into the lens mechanism itself.
>>
>>I am considering abrading off the top mylar coating to expose the copper
>>then bridging the breaks with some very narrow pitch zebra strip. My other
>>idea is to make my own miniature insulation displacement/piercing
>>connector
>>using a stack of razor blade bits sandwiched with insulation layers.
>>
>>The last option would be to use wire links and solder but I think this
>>could
>>only be done with some sort of mechanical micropositioning rig in view of
>>the small sizes involved.
>>
>>I would be interested to hear any thoughts or experiences if anyone has
>>any.
>
> I feel for you, it's a serious oops moment to recover from.
>
> Contact Sony for an idea of cost of fix, so you can place importance
> of fixing yourself in your mind? If you can afford the fix at least
> there's a way out.
>
> You've got stuff to practice with, but I can't see how you're going to
> reliably connect to that fine pitch. Are there accessible places where
> the cut tracks get wider? Do the cut tracks terminate to accessible
> places where you can create another, separate cable to bridge the
> breaks?
>
> IOW, sidestep trying to repair the damage by creating an alternate
> circuit.
>
> Seems to me it's a cable replacement, but that could be sub-assembly
> replacement if the flex also gets glued in place to some smaller parts.
>
> Take it easy, it is not a rush job.
>
> Grant.

The subassembly in question is the lens. Parts of the cable are wrapped
round and glued to the lens body, and the only way to access it is to
completely dismantle the bulk of the camera, more or less reversing the
original manufacturers assembly procedure.

Ian

== 9 of 12 ==
Date: Thurs, Jul 29 2010 4:12 pm
From: "Michael A. Terrell"

Ian P wrote:
>
> "Grant" ?omg@grrr.id.au? wrote in message
> news:vvs356tu89pe9lidcr37ohdtdf9ofkfm7f@4ax.com...
> ? On Thu, 29 Jul 2010 15:17:56 +0100, "Ian P" ?elanman99@yahoo.com? wrote:
> ?
> ??In the course of doing some modifications to a very expensive Sony 3 chip
> ??HD
> ??camcorder I have accidentally cut through 3 tracks on the edge of a mylar?
> ??flexible cable. On the good side the damage is very accessible but the bad
> ??bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally one would
> ??just replace the flex pcb but in practice that would involve dismantling
> ??the
> ??camera and lens to get to all the places the pcb branches out to, and in
> ??some places it actually goes into the lens mechanism itself.
> ??
> ??I am considering abrading off the top mylar coating to expose the copper
> ??then bridging the breaks with some very narrow pitch zebra strip. My other
> ??idea is to make my own miniature insulation displacement/piercing
> ??connector
> ??using a stack of razor blade bits sandwiched with insulation layers.
> ??
> ??The last option would be to use wire links and solder but I think this
> ??could
> ??only be done with some sort of mechanical micropositioning rig in view of
> ??the small sizes involved.
> ??
> ??I would be interested to hear any thoughts or experiences if anyone has
> ??any.
> ?
> ? I feel for you, it's a serious oops moment to recover from.
> ?
> ? Contact Sony for an idea of cost of fix, so you can place importance
> ? of fixing yourself in your mind? If you can afford the fix at least
> ? there's a way out.
> ?
> ? You've got stuff to practice with, but I can't see how you're going to
> ? reliably connect to that fine pitch. Are there accessible places where
> ? the cut tracks get wider? Do the cut tracks terminate to accessible
> ? places where you can create another, separate cable to bridge the
> ? breaks?
> ?
> ? IOW, sidestep trying to repair the damage by creating an alternate
> ? circuit.
> ?
> ? Seems to me it's a cable replacement, but that could be sub-assembly
> ? replacement if the flex also gets glued in place to some smaller parts.
> ?
> ? Take it easy, it is not a rush job.
> ?
> ? Grant.
>
> The subassembly in question is the lens. Parts of the cable are wrapped
> round and glued to the lens body, and the only way to access it is to
> completely dismantle the bulk of the camera, more or less reversing the
> original manufacturers assembly procedure.

Look for a dead unit on ebay for parts.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

== 10 of 12 ==
Date: Thurs, Jul 29 2010 5:40 pm
From: "Arfa Daily"

"Ian P" <elanman99@yahoo.com> wrote in message
news:8bdsinF6u0U1@mid.individual.net...
>
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:bHh4o.61130$0e3.22364@hurricane...
>>
>>
>> "Ian P" <elanman99@yahoo.com> wrote in message
>> news:8bdgspFuetU1@mid.individual.net...
>>> In the course of doing some modifications to a very expensive Sony 3
>>> chip HD camcorder I have accidentally cut through 3 tracks on the edge
>>> of a mylar? flexible cable. On the good side the damage is very
>>> accessible but the bad bit is the tracks are only 0.1mm wide on a 0.2mm
>>> pitch! Ideally one would just replace the flex pcb but in practice that
>>> would involve dismantling the camera and lens to get to all the places
>>> the pcb branches out to, and in some places it actually goes into the
>>> lens mechanism itself.
>>>
>>> I am considering abrading off the top mylar coating to expose the copper
>>> then bridging the breaks with some very narrow pitch zebra strip. My
>>> other idea is to make my own miniature insulation displacement/piercing
>>> connector using a stack of razor blade bits sandwiched with insulation
>>> layers.
>>>
>>> The last option would be to use wire links and solder but I think this
>>> could only be done with some sort of mechanical micropositioning rig in
>>> view of the small sizes involved.
>>>
>>> I would be interested to hear any thoughts or experiences if anyone has
>>> any.
>>>
>>> Cheers
>>>
>>>
>>>
>>> Ian
>>>
>>>
>>
>> Based on my experience of trying to repair accidental damage to
>> flexiprints (yes, it happens to us all no matter how long we've been in
>> the game and how experienced we are !) I think that you are going to
>> struggle to get a fix on one of that tiny pitch. I have had plenty of
>> success with abrading and soldering ones of a slightly greater pitch,
>> doing it with a tiny needle-point soldering tip and under a microscope,
>> and using a single strand from superflex instrument cable, such as is
>> used for better quality meter leads, for instance.
>>
>> I don't know whether this is a commercial job, or one for a friend, or
>> maybe even for yourself, but before you commit to any strategy that's
>> going to waste a lot of time, and end up with no fix at the end of it
>> anyway, the job would probably stand being left for a day or two, before
>> revisiting it with a clear head, to look at how hard replacing the
>> flexiprint would *really* be. I've often found that things that look as
>> though they are going to be a copper-bottomed-gold-plated bitch to do,
>> are actually not so bad, when looked at again after you've calmed down,
>> and forced a degree of 'san fairy ann' into your head over it. If you
>> have a copy of the service manual or can obtain one, a look at the parts
>> list will tell you if replacement is even an option (if you're really
>> unlucky it might be an integral part of the lens assembly) and if it is
>> available, a look at the exploded view diagram, would be helpful to
>> determine how many 'hidden' branches the flexiprint has, and where they
>> go.
>>
>> I really feel for you on this one. I've been there many times over the
>> years ...
>>
>> Good luck with it, and please post back, and let us know how you get on
>> with it :-\
>>
>> Arfa
>
> Arfa
>
> Thanks for your advice. As you postulated this pcb is integral with the
> lens and although I have the full service manual for the camera it give no
> information at all on the lens which is a bought in item (not removable
> though). The job is not really commercial, for a friend or myself but it a
> sort of combination of all three. I caused the damage though and I need to
> repair it because there is not really any alternative.
>
> I have in the past repaired and modified boards and components and used
> thin wire just as you described, this cable though has track and spacing
> widths that are really challenging, and I don't have any microscope.
>
> I have lots of old bits of similar flexible boards and cables so I am
> going to experiment with them.
>
> Ian
>
Another possibility, if you get to the point of 'kill or cure', and
depending on how much space you've got to play with. I have had considerable
success on remaking the ends of flexiprints, that have failed from bending
at the stiffening film at the connection point. You can carefully knife off
the last few mm of cable, then re-expose the print 'fingers' by abrading the
plastic. I actually use a blunt curved scalpel blade. Once the fingers have
been thus exposed, the cable can be reinserted in the connector, and then
the original stiffener pushed back in behind to give a good tension on the
connector again. Suppose now that you could cut right across where the
damage is, and re-expose connector fingers at each cut end. If you could
then obtain connectors, and solder them back to back, you could then use
this as a joint to remake your cable. I realise that with such a fine pitch,
the soldering would not be easy, but at least you would be doing it on the
bench, in the open, and with good light. A strong magnifier would be enough
to be able to see what you are doing, and some liquid flux, and desoldering
braid, should make the job do-able.

Along similar lines, another possibility might be to again cut right across
the cable, and expose the conductors on the upper surface of one end, and
the lower of the other. Then treat it as a surface mount soldering job. If
you use liquid flux, solder paste, and hot air, and do a good job of lining
up the tracks and preventing movement before you start, there's a good
chance of success at making a satisfactory join. Capillary action will pull
the solder onto the tracks, and providing you've been sparing with it, there
shouldn't be any shorts between tracks.

Arfa

== 11 of 12 ==
Date: Fri, Jul 30 2010 12:26 am
From: "N_Cook"

Ian P <elanman99@yahoo.com> wrote in message
news:8bdrqrF2baU1@mid.individual.net...
>
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:i2s5e6$b1d$1@news.eternal-september.org...
> > Ian P <elanman99@yahoo.com> wrote in message
> > news:8bdgspFuetU1@mid.individual.net...
> >> In the course of doing some modifications to a very expensive Sony 3
chip
> > HD
> >> camcorder I have accidentally cut through 3 tracks on the edge of a
> >> mylar?
> >> flexible cable. On the good side the damage is very accessible but the
> >> bad
> >> bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally one
would
> >> just replace the flex pcb but in practice that would involve
dismantling
> > the
> >> camera and lens to get to all the places the pcb branches out to, and
in
> >> some places it actually goes into the lens mechanism itself.
> >>
> >> I am considering abrading off the top mylar coating to expose the
copper
> >> then bridging the breaks with some very narrow pitch zebra strip. My
> >> other
> >> idea is to make my own miniature insulation displacement/piercing
> > connector
> >> using a stack of razor blade bits sandwiched with insulation layers.
> >>
> >> The last option would be to use wire links and solder but I think this
> > could
> >> only be done with some sort of mechanical micropositioning rig in view
of
> >> the small sizes involved.
> >>
> >> I would be interested to hear any thoughts or experiences if anyone has
> > any.
> >>
> >> Cheers
> >>
> >>
> >>
> >> Ian
> >>
> >>
> >
> >
> > Assuming you're not in a stripline-type situation with ground plane/rf
> > considerations, try plaiting some magnet wire and soldering to the 3 pcb
> > solder points at either end of the plaited section of "ribbon", you may
> > have to make a hole through the pcb though.
> >
>
> Its just low level analogue signals but the break is close to the end of
the
> ribbon where the tracks are gold plated to fit in the board connector. The
> copper conductors are encapsulated in the Mylar and drilling through the
> track which is only 0.004" wide would not be easy!
>
> Ian
>
>

No, making hole/s through the pcb, to take the plait, so you can make proper
solder joins to pre-existing solder joints on the ribbon sockets

== 12 of 12 ==
Date: Fri, Jul 30 2010 1:07 am
From: "N_Cook"

Ian P <elanman99@yahoo.com> wrote in message
news:8bdrgeFvrtU1@mid.individual.net...
>
> "Meat Plow" <mhywatt@yahoo.com> wrote in message
> news:pan.2010.07.29.14.56.20@hahahahahahahah.nutz...
> > On Thu, 29 Jul 2010 07:47:37 -0700, William Sommerwerck wrote:
> >
> >> This is "not unlike" fixing a PCB trace. How would you do that?
> >>
> >> What about globbing some eutectic solder over the traces (even though
it
> >> shorts them), then using "something" to break the solder into
individual
> >> "strands" while it's still liquid?
> >>
> >> I'm wondering whether zebra strip would be conductive enough? It might
> >> not matter over such a short (ar, ar) distance.
> >>
> >> I wish you success. And if this happened this morning, please put it
> >> aside and relax. Work on something else, something easy, and try to
> >> forget about this problem for the time being.
> >
> > Flexible pcb connector as in a ribbon connector? I've had some limited
> > success repairing these with conductive paint designed to repair
> > automotive window heaters.
>
> Its a paper thin flexible pcb, golden brown in colour which I think is
made
> from Mylar. Because of the narrowness of the tracks and their spacing I
> doubt it could be done with paint.
>
> Ian
>
>

If heat resistant then probably kapton tape. If signal levels and you have a
fairy godmother then anisotropic tape is another possibility , if you can
bare back to the underlying condusctors .

==============================================================================
TOPIC: Midiverb ii issues?
http://groups.google.com/group/sci.electronics.repair/t/aaedd7aef36420d1?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Jul 29 2010 10:41 am
From: "Michael A. Terrell"

Meat Plow wrote:
>
> On Thu, 29 Jul 2010 09:28:33 +0100, Arfa Daily wrote:
>
> > <snip>
> >
> >
> >>> Interesting. I wonder why the difference ? A few years back - say 10
> >>> or so -
> >>> I would have said that I saw as many short circuit electrolytics, as
> >>> any other problems with them such as open circuit, low value, leaking,
> >>> bulging
> >>> etc. Now though, short circuit is comparatively rare. As to cathode
> >>> caps, I
> >>> think that I have probably seen more that were open circuit than
> >>> short. Used
> >>> to be a big problem in the frame output and audio output stages of TV
> >>> sets,
> >>> back in the day ...
> >>
> >>
> >> Sprague had high standards, but you paid for it. Japanese crap hit
> >> the US hard in the early '70s and you saw a lot more failed
> >> electrolytics. Sprague started shutting down their plants as demand
> >> for high quality electrolytics dropped. I still have a roll of
> >> aluminized mylar from the Orlando plant, along with a partial roll of
> >> 'component lead' they used on their famous 'Orange Drop' capacitors.
> >
> > Now there's another interesting thing. I wouldn't have thought that
> > Orlando, given the extremes of humidity that it suffers, would have been
> > a very good place for manufacturing capacitors, or was it just 'wet'
> > electrolytics that were made there ? Or was the whole plant
> > environment-controlled ? Guess you wouldn't be able to afford to do that
> > these days ...
> >
> > Arfa
>
> I don't suppose a plant manufacturing capacitors has to be very big. At
> least the assembly building. It's easy enough to imagine a climate
> controlled assembly room. And Mike is right about the history of
> capacitors. I lived through the era when manufacturing stopped giving a
> shit about quality over pumping out volumes of crap.

Sprague continued to make them, but most manufacturers had been taken
over by MBA bean counters by then. They were still making high quality
parts, till Vishay bought them.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

==============================================================================
TOPIC: Motorola Cross Reference program...
http://groups.google.com/group/sci.electronics.repair/t/f71ee2145e5900e4?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Jul 29 2010 10:45 am
From: "Michael A. Terrell"

Meat Plow wrote:
>
> On Thu, 29 Jul 2010 00:10:31 +0000, John Robertson wrote:
>
> > Years ago (1980s?) I had a program from Motorola on 1.4" floppy that
> > would allow me to input a characteristic and the program would reply
> > with a list of transistors that matched. I have long since lost it...
> >
> > Has anyone got a copy or know of something similar? Motorola was
> > handing this out to anyone that asked, so I would assume it is
> > essentially public domain.
> >
>
> Didn't Motorola migrate this to a web-based interface?

Yes, before they spun off ON Semiconductors. Then a lot of useful
information was taken down. All their old data sheets and application
notes were hosted by a contractor and it all disappeared, over night.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

==============================================================================
TOPIC: Grain-of-wheat bulbs
http://groups.google.com/group/sci.electronics.repair/t/80801ab1fbd67e8f?hl=en
==============================================================================

== 1 of 7 ==
Date: Thurs, Jul 29 2010 11:07 am
From: "Paul Hovnanian P.E."

I'm looking for a couple of these to repair some (antique) equipment. They
should be 1.5V, about 30mA and produce a relatively 'white' light at this
current. Some Radio Shack 6V, 100mA bulbs draw approximately the correct
current at 1.5V, but they are too reddish and dim to be of any use.

These are used in an old photographic light meter as a null indicator. LEDs
won't work at this voltage level (too dim and no where near linear
brightness vs voltage).

--
Paul Hovnanian paul@hovnanian.com
----------------------------------------------------------------------
Have gnu, will travel.

== 2 of 7 ==
Date: Thurs, Jul 29 2010 11:20 am
From: dplatt@radagast.org (Dave Platt)

In article <Noadne83-tm2XszRnZ2dnUVZ_sKdnZ2d@posted.isomediainc>,
Paul Hovnanian P.E. <paul@hovnanian.com> wrote:

>I'm looking for a couple of these to repair some (antique) equipment. They
>should be 1.5V, about 30mA and produce a relatively 'white' light at this
>current. Some Radio Shack 6V, 100mA bulbs draw approximately the correct
>current at 1.5V, but they are too reddish and dim to be of any use.
>
>These are used in an old photographic light meter as a null indicator. LEDs
>won't work at this voltage level (too dim and no where near linear
>brightness vs voltage).

First Googling turns up some bulbs offered by Kit Kraft, for dollhouse
use: http://www.kitkraft.biz/product.php?productid=5582

Stated as 1.5 - 3 volts, current draw not stated.

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of 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!

== 3 of 7 ==
Date: Thurs, Jul 29 2010 2:17 pm
From: Piotr Piatek

On Thu, 29 Jul 2010 11:07:21 -0700, "Paul Hovnanian P.E." wrote:

>I'm looking for a couple of these to repair some (antique) equipment. They
>should be 1.5V, about 30mA and produce a relatively 'white' light at this
>current.

You could cannibalize a cheap LCD watch. They use tiny 1.5V bulbs to
backlit the display.

Piotr

== 4 of 7 ==
Date: Thurs, Jul 29 2010 2:47 pm
From: Grant

On Thu, 29 Jul 2010 11:07:21 -0700, "Paul Hovnanian P.E." <paul@hovnanian.com> wrote:

If you could add an opamp for voltage to current, you might be able to
use a LED. Otherwise more shopping around, perhaps hobby model shops?

Grant.

== 5 of 7 ==
Date: Thurs, Jul 29 2010 4:05 pm
From: Archon

On 7/29/2010 2:07 PM, Paul Hovnanian P.E. wrote:
> I'm looking for a couple of these to repair some (antique) equipment. They
> should be 1.5V, about 30mA and produce a relatively 'white' light at this
> current. Some Radio Shack 6V, 100mA bulbs draw approximately the correct
> current at 1.5V, but they are too reddish and dim to be of any use.
>
> These are used in an old photographic light meter as a null indicator. LEDs
> won't work at this voltage level (too dim and no where near linear
> brightness vs voltage).
>

Ebay #> 120598027723

Have to hack the cute lampshades off maybe?
JC

== 6 of 7 ==
Date: Thurs, Jul 29 2010 4:20 pm
From: Archon

On 7/29/2010 7:05 PM, Archon wrote:
> On 7/29/2010 2:07 PM, Paul Hovnanian P.E. wrote:
>> I'm looking for a couple of these to repair some (antique) equipment.
>> They
>> should be 1.5V, about 30mA and produce a relatively 'white' light at this
>> current. Some Radio Shack 6V, 100mA bulbs draw approximately the correct
>> current at 1.5V, but they are too reddish and dim to be of any use.
>>
>> These are used in an old photographic light meter as a null indicator.
>> LEDs
>> won't work at this voltage level (too dim and no where near linear
>> brightness vs voltage).
>>
>
> Ebay #> 120598027723
>
> Have to hack the cute lampshades off maybe?
> JC
or you could try

http://www.miniatronics.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=1_1

== 7 of 7 ==
Date: Thurs, Jul 29 2010 9:25 pm
From: David Nebenzahl

On 7/29/2010 11:07 AM Paul Hovnanian P.E. spake thus:

> I'm looking for a couple of these to repair some (antique) equipment. They
> should be 1.5V, about 30mA and produce a relatively 'white' light at this
> current. Some Radio Shack 6V, 100mA bulbs draw approximately the correct
> current at 1.5V, but they are too reddish and dim to be of any use.
>
> These are used in an old photographic light meter as a null indicator. LEDs
> won't work at this voltage level (too dim and no where near linear
> brightness vs voltage).

Is that meter by any chance a Gossen? the type with two bulbs that light
up equally bright when the dial is adjusted correctly? I had one of
those when I was a kid. Luna Pro?

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

==============================================================================
TOPIC: Isopropyl Alcohol for Cleaning Flux
http://groups.google.com/group/sci.electronics.repair/t/a7a3663fd81cf5bd?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Jul 29 2010 3:24 pm
From: "krw@att.bizzzzzzzzzzzz"

On Thu, 29 Jul 2010 13:09:34 GMT, zekfrivo@zekfrivolous.com (GregS) wrote:

>In article <jrmu469u6g971p30bt3i94oool6vj2k8ub@4ax.com>, "krw@att.bizzzzzzzzzzzz" <krw@att.bizzzzzzzzzzzz> wrote:
>>On Tue, 27 Jul 2010 13:50:11 GMT, zekfrivo@zekfrivolous.com (GregS) wrote:
>>
>>>In article <g31s46p08a2d3iasq94q31guq46k07n7ra@4ax.com>,
>> "krw@att.bizzzzzzzzzzzz" <krw@att.bizzzzzzzzzzzz> wrote:
>>>>On Mon, 26 Jul 2010 19:04:22 GMT, zekfrivo@zekfrivolous.com (GregS) wrote:
>>>>
>>>>>In article <slrni4rlsb.9v8.gsm@cable.mendelson.com>, gsm@mendelson.com
>> wrote:
>>>>>>GregS wrote:
>>>>>>
>>>>>>> 95% is a very good figure. I actually use the NON-denatured stuff.
>>>>>>
>>>>>>How about the drinking stuff? (95% "grain" alcohol).
>>>>>>
>>>>>>Here I can by a "fifth" (750ml) for less than 250ml of 70% Isopropyl.
>>>>>>
>>>>>
>>>>>
>>>>>Yes I was reffering to the ethanol drinkable stuff that is not taxed.
>>>>>Been used for years in medical parties.
>>>>
>>>>Not a wise move. The un-taxed stuff (not for human consumption) often
>>>>contains benzene.
>>>
>>>Thats the 99% stuff that contains benzene.
>>
>>Much of the untaxed ethanol uses the benzene process.
>
>None of the 95%.

I wouldn't bet my life on it.

==============================================================================
TOPIC: HOT ANUSHKA PICTURES FOR BOLLYWOOD FANS
http://groups.google.com/group/sci.electronics.repair/t/a0c302cf9c8ff527?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Jul 29 2010 5:22 pm
From: ANUSHKA

HOT ANUSHKA PICTURES FOR BOLLYWOOD FANS
-------------------------------------
http://sites.google.com/site/anushkaphotosalert

==============================================================================
TOPIC: Need schematic or service manual - Advent
http://groups.google.com/group/sci.electronics.repair/t/b7b89d2a59488e9a?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Jul 29 2010 5:55 pm
From: "Mark Zacharias"

Need info on the Advent Powered Louspeaker.

I used to have this stuff somewhere...

Thanks,

Mark Z.

--
"I can't die until the government finds a safe place to bury my liver."

==============================================================================
TOPIC: hissing sound coming from behind woofer on one side AR11
http://groups.google.com/group/sci.electronics.repair/t/3a9cce9766f809ce?hl=en
==============================================================================

== 1 of 2 ==
Date: Thurs, Jul 29 2010 7:39 pm
From: Amanda Ripanykhazov

On Jul 29, 12:43 pm, zekfr...@zekfrivolous.com (GregS) wrote:
> In article <7b33e37c-d03a-4938-aa3a-761ada39d...@5g2000yqz.googlegroups.com>, Amanda Ripanykhazov <dmanzal...@googlemail.com> wrote:
>
>
>
>
>
> >On Jul 26, 4:11=A0am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> >> "Amanda Ripanykhazov" <dmanzal...@googlemail.com> wrote in message
>
> >>news:8f36b444-2b05-4f98-85e1-d79583ce9c63@g19g2000yqc.googlegroups.com...
>
> >> > On Jul 24, 7:21 am, bz <WQAHBGMXS...@spammotel.com> wrote:
> >> >> Amanda Ripanykhazov wrote:
> >> >> > Anyone know what this means? This hissing sound isnt constant, it is
> >> >> > irregular: =A0It isnt related to the music or any movement of the co=
> >ne
> >> >> > or any signal put through it, though it doesnt happen when no sound =
> >is
> >> >> > put through the speaker.
>
> >> >> > Frankly it sounds more mechancial than electronic (as if there is
> >> >> > something behind there!) but as I say, it isnt related to whatever i=
> >s
> >> >> > coming through the speaker though it does increase and decrease with
> >> >> > adjustment of the volume control. =A0Andit is louder than most signa=
> >ls
> >> >> > put through the woofer itself??
>
> >> >> > Is it indicative of some pot in the crossover needing cleaning or is
> >> >> > there something else going on please? (I have seen reference to peop=
> >le
> >> >> > improving the sound of AR11s by bypassing the tone controls in the
> >> >> > speaker completely). =A0This speaker is quite elderly and I would
> >> >> > imagine that if it does use mechanical pots, they must be fairly dir=
> >ty
> >> >> > by now
>
> >> >> I know it is a silly question, but are you SURE that the hiss isn't
> >> >> coming out of your amplifier?
> >> >> (have you put a scope on the speaker lines or substituted either speak=
> >er
> >> >> or amp?)
>
> >> >> =A0From your description, it isn't clear to me that you have eliminate=
> >d the
> >> >> 'more obvious' possibility that your amplifier is putting out white
> >> >> noise, perhaps intermittently varying in amplitude.- Hide quoted text =
> >-
>
> >> >> - Show quoted text -
>
> >> > Yeah, switching one speaker pretty much solved that one.
>
> >> What, solved it as in proved that the amplifier *was* the cause, or solve=
> >d
> >> it as in it wasn't ?
>
> >> Arfa- Hide quoted text -
>
> >> - Show quoted text -
>
> >When I took out the speaker and put in another one, the hissing sound
> >stopped? When I put the speaker in again, the hissing sound started
> >again
>
> I don't know if my question was ever answered. Where is the hissing
> comming from ? Behind speakers means behind the box.
>
> If you can't tell from listening, use a piece of tubing to get location.
> You can get it down to less than an inch.
>
> greg- Hide quoted text -
>
> - Show quoted text -

I thought I made this point in the second posting by saying what I did
to try to trace it by pushing in the woofer (you cant push in a
tweeter that easily), the sound is coming from behind the woofer.

== 2 of 2 ==
Date: Fri, Jul 30 2010 1:05 am
From: "Arfa Daily"

"Amanda Ripanykhazov" <dmanzaluni@googlemail.com> wrote in message
news:c1be9778-423f-4f2f-8a20-49b444da7375@j9g2000yqn.googlegroups.com...
> On Jul 29, 12:43 pm, zekfr...@zekfrivolous.com (GregS) wrote:
>> In article
>> <7b33e37c-d03a-4938-aa3a-761ada39d...@5g2000yqz.googlegroups.com>, Amanda
>> Ripanykhazov <dmanzal...@googlemail.com> wrote:
>>
>>
>>
>>
>>
>> >On Jul 26, 4:11=A0am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
>> >> "Amanda Ripanykhazov" <dmanzal...@googlemail.com> wrote in message
>>
>> >>news:8f36b444-2b05-4f98-85e1-d79583ce9c63@g19g2000yqc.googlegroups.com...
>>
>> >> > On Jul 24, 7:21 am, bz <WQAHBGMXS...@spammotel.com> wrote:
>> >> >> Amanda Ripanykhazov wrote:
>> >> >> > Anyone know what this means? This hissing sound isnt constant, it
>> >> >> > is
>> >> >> > irregular: =A0It isnt related to the music or any movement of the
>> >> >> > co=
>> >ne
>> >> >> > or any signal put through it, though it doesnt happen when no
>> >> >> > sound =
>> >is
>> >> >> > put through the speaker.
>>
>> >> >> > Frankly it sounds more mechancial than electronic (as if there is
>> >> >> > something behind there!) but as I say, it isnt related to
>> >> >> > whatever i=
>> >s
>> >> >> > coming through the speaker though it does increase and decrease
>> >> >> > with
>> >> >> > adjustment of the volume control. =A0Andit is louder than most
>> >> >> > signa=
>> >ls
>> >> >> > put through the woofer itself??
>>
>> >> >> > Is it indicative of some pot in the crossover needing cleaning or
>> >> >> > is
>> >> >> > there something else going on please? (I have seen reference to
>> >> >> > peop=
>> >le
>> >> >> > improving the sound of AR11s by bypassing the tone controls in
>> >> >> > the
>> >> >> > speaker completely). =A0This speaker is quite elderly and I would
>> >> >> > imagine that if it does use mechanical pots, they must be fairly
>> >> >> > dir=
>> >ty
>> >> >> > by now
>>
>> >> >> I know it is a silly question, but are you SURE that the hiss isn't
>> >> >> coming out of your amplifier?
>> >> >> (have you put a scope on the speaker lines or substituted either
>> >> >> speak=
>> >er
>> >> >> or amp?)
>>
>> >> >> =A0From your description, it isn't clear to me that you have
>> >> >> eliminate=
>> >d the
>> >> >> 'more obvious' possibility that your amplifier is putting out white
>> >> >> noise, perhaps intermittently varying in amplitude.- Hide quoted
>> >> >> text =
>> >-
>>
>> >> >> - Show quoted text -
>>
>> >> > Yeah, switching one speaker pretty much solved that one.
>>
>> >> What, solved it as in proved that the amplifier *was* the cause, or
>> >> solve=
>> >d
>> >> it as in it wasn't ?
>>
>> >> Arfa- Hide quoted text -
>>
>> >> - Show quoted text -
>>
>> >When I took out the speaker and put in another one, the hissing sound
>> >stopped? When I put the speaker in again, the hissing sound started
>> >again
>>
>> I don't know if my question was ever answered. Where is the hissing
>> comming from ? Behind speakers means behind the box.
>>
>> If you can't tell from listening, use a piece of tubing to get location.
>> You can get it down to less than an inch.
>>
>> greg- Hide quoted text -
>>
>> - Show quoted text -
>
> I thought I made this point in the second posting by saying what I did
> to try to trace it by pushing in the woofer (you cant push in a
> tweeter that easily), the sound is coming from behind the woofer.

I'm thinking now that this is a windup. Looking at the the account that this
has come from.

dmanzaluni ?

Yes, I think that's maybe true ...

Arfa

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