Toshiba TV29C90 problem; Image fades to black...

[Dave Plowman (News)]

In article
<b0db41bd-e885-4693-a2e3-050b63ff4d99@z66g2000hsc.googlegroups.com>,
<schnide@btinternet.com> wrote:

It could be you could modify the Nokia one to use headphones of your
choice - ie using the Nokia electronics. But that PDF doesn't give the
spec of the headphones they supply, and the power amp may not be
suitable for standard ones.

It might be possible to source a USB input headphone amp which will
drive conventional ones. Although it might be bigger than the phone
itself ;-)

Dave,

Thank you for all this, it's incredibly helpful. I had considered the
possiblity of adapting an existing set of Nokia headphones to have a
3.5mm jack coming out of the electronics unit instead of the earbuds
themselves, but this would be slightly messy and ultimately result in a
lot of wire.

I'm afraid that would be the price to be paid. It's really not practical
to make things as a one off as small as the factory can.

As you appear to be something of an expert,

Heh heh - enthusiastic amateur would be nearer it. With *some* expertise
in *some* things.

at least compared to myself,
do you know of anywhere who offers a service that would rehouse the
section of the electronics piece that converts to the digital signal in
small plastic casing with a 3.5mm jack for me?

Afraid I don't. It's the sort of thing I might well attempt for myself -
but not a stranger. And don't really know of anywhere providing such a
service - which would be very costly anyway, due to the time involved for
any one off.

Despite my poor soldering skills, I'd do this myself, except when I took
my official Nokia headset apart it had what appeared to be fiber optic
wiring instead of anything I could take a soldering iron too. I imagine
this is standard now to allow thinner leads, but doesn't help me solve
my problem.

It's probably a mixture of fibres and copper to provide extreme
flexibility and strength. You normally terminate this sort of flex with a
crimped joint.

Many thanks as always, myself and others are hanging on a solution -

If many want this I'm surprised an accessory maker hasn't supplied what
you need.

--
*Indian Driver - Smoke signals only*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Dave Plowman (News)]

In article
<b0db41bd-e885-4693-a2e3-050b63ff4d99@z66g2000hsc.googlegroups.com>,
<schnide@btinternet.com> wrote:

It could be you could modify the Nokia one to use headphones of your
choice - ie using the Nokia electronics. But that PDF doesn't give the
spec of the headphones they supply, and the power amp may not be
suitable for standard ones.

It might be possible to source a USB input headphone amp which will
drive conventional ones. Although it might be bigger than the phone
itself ;-)

Dave,

Thank you for all this, it's incredibly helpful. I had considered the
possiblity of adapting an existing set of Nokia headphones to have a
3.5mm jack coming out of the electronics unit instead of the earbuds
themselves, but this would be slightly messy and ultimately result in a
lot of wire.

I'm afraid that would be the price to be paid. It's really not practical
to make things as a one off as small as the factory can.

As you appear to be something of an expert,

Heh heh - enthusiastic amateur would be nearer it. With *some* expertise
in *some* things.

at least compared to myself,
do you know of anywhere who offers a service that would rehouse the
section of the electronics piece that converts to the digital signal in
small plastic casing with a 3.5mm jack for me?

Afraid I don't. It's the sort of thing I might well attempt for myself -
but not a stranger. And don't really know of anywhere providing such a
service - which would be very costly anyway, due to the time involved for
any one off.

Despite my poor soldering skills, I'd do this myself, except when I took
my official Nokia headset apart it had what appeared to be fiber optic
wiring instead of anything I could take a soldering iron too. I imagine
this is standard now to allow thinner leads, but doesn't help me solve
my problem.

It's probably a mixture of fibres and copper to provide extreme
flexibility and strength. You normally terminate this sort of flex with a
crimped joint.

Many thanks as always, myself and others are hanging on a solution -

If many want this I'm surprised an accessory maker hasn't supplied what
you need.

--
*Indian Driver - Smoke signals only*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[bz]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:483537EF.A19D7C3F@hotmail.com:

gareth magennis wrote:

"orange" <orange47@gmail.com> wrote in message

Is it safe to keep the CMOS chips (RAM) in plastic box?
if not, can it be modified to be safe somehow, I just don't have any
alternative..

Wrap some aluminium foil around a small piece of expanded polystyrene,
then you can just push the chips into the sandwich and keep the lot in
a plastic box. The foil shorts all the pins together so there can be
no potential difference between any.

Aluminium foil is a BAD idea. In the event that there is any appreciable
charge on a given pin, pushing it into aluminium foil will discharge it
*quickly* and the resulting current may kill it.

It is NOT the current that kills CMOS, it is high VOLTAGE that punches
holes in the insulating layers inside the chip. [I am not aware of ANY chip
families where tiny CURRENTS would be a hazard].

As the conductors are quite small, it only requires a surplus/deficit of a
"few" electrons to build up a high voltage.

When the chip is in a circuit, there will be much higher currents charging
and discharging the

You want to avoid anything that may have accumulated a large surplus or
deficit of electrons.

As long as the aluminum foil is not at a high static voltage, the chances
of damage are quite small.

Hold the chip in one hand, the aluminum foil in the other and run your
finger along the leads before you bring the chip into contact with the
aluminum foil, if you want to 'slowly discharge' any charge that might have
built up.
(this assumes clean hands with normal skin resistance)
If you want to be ULTRA safe, make sure you touch the Vcc and Gnd pins
FIRST.

Always use high resistance material for storing ICs like the anyi-static
black foam material. This allows any charge to 'leak' away slowly and
safely.

--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:483537EF.A19D7C3F@hotmail.com:

gareth magennis wrote:

"orange" <orange47@gmail.com> wrote in message

Is it safe to keep the CMOS chips (RAM) in plastic box?
if not, can it be modified to be safe somehow, I just don't have any
alternative..

Wrap some aluminium foil around a small piece of expanded polystyrene,
then you can just push the chips into the sandwich and keep the lot in
a plastic box. The foil shorts all the pins together so there can be
no potential difference between any.

Aluminium foil is a BAD idea. In the event that there is any appreciable
charge on a given pin, pushing it into aluminium foil will discharge it
*quickly* and the resulting current may kill it.

It is NOT the current that kills CMOS, it is high VOLTAGE that punches
holes in the insulating layers inside the chip. [I am not aware of ANY chip
families where tiny CURRENTS would be a hazard].

As the conductors are quite small, it only requires a surplus/deficit of a
"few" electrons to build up a high voltage.

When the chip is in a circuit, there will be much higher currents charging
and discharging the

You want to avoid anything that may have accumulated a large surplus or
deficit of electrons.

As long as the aluminum foil is not at a high static voltage, the chances
of damage are quite small.

Hold the chip in one hand, the aluminum foil in the other and run your
finger along the leads before you bring the chip into contact with the
aluminum foil, if you want to 'slowly discharge' any charge that might have
built up.
(this assumes clean hands with normal skin resistance)
If you want to be ULTRA safe, make sure you touch the Vcc and Gnd pins
FIRST.

Always use high resistance material for storing ICs like the anyi-static
black foam material. This allows any charge to 'leak' away slowly and
safely.

--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[Smitty Two]

In article <n6KdnVngm_e6jKjVnZ2dnUVZ_qXinZ2d@earthlink.com>,
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

dBc wrote:

Greetings -Senin..

Why is your housekeeper even close enough around your answering
machine to 'accidentally' do this?

Solution, make it clear to either stay away from personal electronics
and especially your telephone answering machine or she will be
replaced. Simple as that.. Otherwise, this is likely to happen [yet]
again.

The "oh, sorry about that.." routine doesn't cut it unless she has
been with you for years and this just happened out of the blue. I will
tell you that the housekeepers love to tell stories like this with
other housekeepers about how they do such things for jollies.. Senin,
IF it was truly important to you, then it's time for the bill payer to
be stern, otherwise, she won't consider it any more important than you
do!


How do you know it wasn't a low hanging power cord that got caught
with the vacuum cleaner, or some other stupid accident that could have
been prevented by a proper installation? Or even a worn out outlet that
let the wall wart fall out from the vibration? You are quick to condemn
people with little or no information.

Nice guesses, but dBc obviously knows nothing about cleaning.
Housekeepers are supposed to clean things (by definition,) including
answering machines. They gather dust and dirty fingerprints just like
phones and keyboards do. It's easy to push buttons randomly when you're
cleaning something like that.

 

[Smitty Two]

In article <n6KdnVngm_e6jKjVnZ2dnUVZ_qXinZ2d@earthlink.com>,
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

dBc wrote:

Greetings -Senin..

Why is your housekeeper even close enough around your answering
machine to 'accidentally' do this?

Solution, make it clear to either stay away from personal electronics
and especially your telephone answering machine or she will be
replaced. Simple as that.. Otherwise, this is likely to happen [yet]
again.

The "oh, sorry about that.." routine doesn't cut it unless she has
been with you for years and this just happened out of the blue. I will
tell you that the housekeepers love to tell stories like this with
other housekeepers about how they do such things for jollies.. Senin,
IF it was truly important to you, then it's time for the bill payer to
be stern, otherwise, she won't consider it any more important than you
do!


How do you know it wasn't a low hanging power cord that got caught
with the vacuum cleaner, or some other stupid accident that could have
been prevented by a proper installation? Or even a worn out outlet that
let the wall wart fall out from the vibration? You are quick to condemn
people with little or no information.

Nice guesses, but dBc obviously knows nothing about cleaning.
Housekeepers are supposed to clean things (by definition,) including
answering machines. They gather dust and dirty fingerprints just like
phones and keyboards do. It's easy to push buttons randomly when you're
cleaning something like that.

 

[bz]

Wiebe Cazemier <wiebe@halfgaar.net> wrote in news:d595a$48355326$d4cc82be
$13740@cache5.tilbu1.nb.home.nl:

Regunned? Is that possible?

Google for
CRT repairs





--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+spr@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

Wiebe Cazemier <wiebe@halfgaar.net> wrote in news:d595a$48355326$d4cc82be
$13740@cache5.tilbu1.nb.home.nl:

Regunned? Is that possible?

Google for
CRT repairs





--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+spr@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[Gareth Magennis]

"Smitty Two" <prestwhich@earthlink.net> wrote in message
newsrestwhich-24F748.06400122052008@news.lga.highwinds-media.com...

In article <n6KdnVngm_e6jKjVnZ2dnUVZ_qXinZ2d@earthlink.com>,
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

dBc wrote:

Greetings -Senin..

Why is your housekeeper even close enough around your answering
machine to 'accidentally' do this?

Solution, make it clear to either stay away from personal electronics
and especially your telephone answering machine or she will be
replaced. Simple as that.. Otherwise, this is likely to happen [yet]
again.

The "oh, sorry about that.." routine doesn't cut it unless she has
been with you for years and this just happened out of the blue. I will
tell you that the housekeepers love to tell stories like this with
other housekeepers about how they do such things for jollies.. Senin,
IF it was truly important to you, then it's time for the bill payer to
be stern, otherwise, she won't consider it any more important than you
do!


How do you know it wasn't a low hanging power cord that got caught
with the vacuum cleaner, or some other stupid accident that could have
been prevented by a proper installation? Or even a worn out outlet that
let the wall wart fall out from the vibration? You are quick to condemn
people with little or no information.

Nice guesses, but dBc obviously knows nothing about cleaning.
Housekeepers are supposed to clean things (by definition,) including
answering machines. They gather dust and dirty fingerprints just like
phones and keyboards do. It's easy to push buttons randomly when you're
cleaning something like that.

dBc is either a Troll or a White South African.



Gareth.

 

[N_Cook]

Mr. Land <graftonfot@yahoo.com> wrote in message
news:c6f28ccb-9d1d-4ce2-a4c4-dc2459cda540@i76g2000hsf.googlegroups.com...

Hi, I'm wondering if anyone here has attempted (and hopefully had
success with) repairing their own Saab SID display.

These System Information Displays are renowned for having segments of
the display go dead. The problem is caused by faulty connections
between a ribbon conductor that connects pads at one edge of the main
board to the (separate) display unit. My understanding is that Saab
chose to attach (and connect) the ribbon conductor to the main board
pads using some sort of conductive adhesive. Over time, the
connections become intermittent and you start losing rows and/or
columns of the segment display.

There are a myriad of fixes for this on the Internet along with
replacement SIDs for sale on places like eBay. Most of the fixes
involve applying additional pressure to the adhered connections to try
to reestablish continuity. I've tried these but those that give some
improvement don't last.

So I am wondering if anyone has tried to repair one of these
themselves and what success you've had. I was thinking of trying to
replace the existing ribbon cable with either something thicker or
something wire-based so that I could perhaps solder the connections to
the board using a low temp solder.

Any info/insight/experiences are appreciated...

Can you rob zebra strip from some suitable sort of scrap equipment and then
add pressure somehow?. How removable is the original stuff?

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

 

[N_Cook]

Mr. Land <graftonfot@yahoo.com> wrote in message
news:c6f28ccb-9d1d-4ce2-a4c4-dc2459cda540@i76g2000hsf.googlegroups.com...

Hi, I'm wondering if anyone here has attempted (and hopefully had
success with) repairing their own Saab SID display.

These System Information Displays are renowned for having segments of
the display go dead. The problem is caused by faulty connections
between a ribbon conductor that connects pads at one edge of the main
board to the (separate) display unit. My understanding is that Saab
chose to attach (and connect) the ribbon conductor to the main board
pads using some sort of conductive adhesive. Over time, the
connections become intermittent and you start losing rows and/or
columns of the segment display.

There are a myriad of fixes for this on the Internet along with
replacement SIDs for sale on places like eBay. Most of the fixes
involve applying additional pressure to the adhered connections to try
to reestablish continuity. I've tried these but those that give some
improvement don't last.

So I am wondering if anyone has tried to repair one of these
themselves and what success you've had. I was thinking of trying to
replace the existing ribbon cable with either something thicker or
something wire-based so that I could perhaps solder the connections to
the board using a low temp solder.

Any info/insight/experiences are appreciated...

Can you rob zebra strip from some suitable sort of scrap equipment and then
add pressure somehow?. How removable is the original stuff?

--
General electronic repairs, most things repaired, other than TVs and PCs
http://www.divdev.fsnet.co.uk/repairs.htm

Diverse Devices, Southampton, England

 

[gareth magennis]

"Mr. Land" <graftonfot@yahoo.com> wrote in message
news:c6f28ccb-9d1d-4ce2-a4c4-dc2459cda540@i76g2000hsf.googlegroups.com...

Hi, I'm wondering if anyone here has attempted (and hopefully had
success with) repairing their own Saab SID display.

These System Information Displays are renowned for having segments of
the display go dead. The problem is caused by faulty connections
between a ribbon conductor that connects pads at one edge of the main
board to the (separate) display unit. My understanding is that Saab
chose to attach (and connect) the ribbon conductor to the main board
pads using some sort of conductive adhesive. Over time, the
connections become intermittent and you start losing rows and/or
columns of the segment display.

There are a myriad of fixes for this on the Internet along with
replacement SIDs for sale on places like eBay. Most of the fixes
involve applying additional pressure to the adhered connections to try
to reestablish continuity. I've tried these but those that give some
improvement don't last.

So I am wondering if anyone has tried to repair one of these
themselves and what success you've had. I was thinking of trying to
replace the existing ribbon cable with either something thicker or
something wire-based so that I could perhaps solder the connections to
the board using a low temp solder.

Any info/insight/experiences are appreciated...

IME I would have to say this is a major design fault that has no solution,
other than the adding pressure bodges you have already seen, that merely
address the symptoms, not effecting a cure. I very quickly gave up
attempting to repair similar ribbon connectors found in
synthesisers/keyboards etc.

Hard wiring 200 or so connections each end at this density is really beyond
the realms of sensibility, even if it could be done with some degree of
reliability.

Your suggestion of low temp solder is probably the best you could hope for,
given the ribbon connector is plastic.

There is a product call Chipquick http://www.chipquikinc.com/ which is an
alloy that melts at 58 degrees C. It might be possible, using the right
fluxes and techniques, to solder the plastic ribbon connector to the PCB,
but I suspect you might have to spend a good few months and use up quite a
few Saab displays before you get this to work properly.




Gareth.

 

[gareth magennis]

"Mr. Land" <graftonfot@yahoo.com> wrote in message
news:c6f28ccb-9d1d-4ce2-a4c4-dc2459cda540@i76g2000hsf.googlegroups.com...

Hi, I'm wondering if anyone here has attempted (and hopefully had
success with) repairing their own Saab SID display.

These System Information Displays are renowned for having segments of
the display go dead. The problem is caused by faulty connections
between a ribbon conductor that connects pads at one edge of the main
board to the (separate) display unit. My understanding is that Saab
chose to attach (and connect) the ribbon conductor to the main board
pads using some sort of conductive adhesive. Over time, the
connections become intermittent and you start losing rows and/or
columns of the segment display.

There are a myriad of fixes for this on the Internet along with
replacement SIDs for sale on places like eBay. Most of the fixes
involve applying additional pressure to the adhered connections to try
to reestablish continuity. I've tried these but those that give some
improvement don't last.

So I am wondering if anyone has tried to repair one of these
themselves and what success you've had. I was thinking of trying to
replace the existing ribbon cable with either something thicker or
something wire-based so that I could perhaps solder the connections to
the board using a low temp solder.

Any info/insight/experiences are appreciated...

IME I would have to say this is a major design fault that has no solution,
other than the adding pressure bodges you have already seen, that merely
address the symptoms, not effecting a cure. I very quickly gave up
attempting to repair similar ribbon connectors found in
synthesisers/keyboards etc.

Hard wiring 200 or so connections each end at this density is really beyond
the realms of sensibility, even if it could be done with some degree of
reliability.

Your suggestion of low temp solder is probably the best you could hope for,
given the ribbon connector is plastic.

There is a product call Chipquick http://www.chipquikinc.com/ which is an
alloy that melts at 58 degrees C. It might be possible, using the right
fluxes and techniques, to solder the plastic ribbon connector to the PCB,
but I suspect you might have to spend a good few months and use up quite a
few Saab displays before you get this to work properly.




Gareth.

 

[Michael Kennedy]

"D" <tarb@bk.ru> wrote in message
news:8176d4f2-bd92-4478-9f41-94c231ab1ec3@26g2000hsk.googlegroups.com...
On May 22, 11:19 am, "Michael Kennedy" <Mikek...@remthis.comcast.net>
wrote:

"D" <t...@bk.ru> wrote in message

news:1da0dd27-604a-47dc-a759-7635083f9b5d@c58g2000hsc.googlegroups.com...
On May 21, 6:18 pm, ransley <Mark_Rans...@yahoo.com> wrote:





On May 21, 7:02 am, D <t...@bk.ru> wrote:

On May 21, 3:54 pm, ransley <Mark_Rans...@yahoo.com> wrote:> On May
21,
5:30 am, D <t...@bk.ru> wrote:

Hello!
Why does a panoramic video (in an evening or inside a building,
shot
by Sony HC5E camcorder) look like the frame rate is about 10 fps?
My
11-year old JVC VHS-C camcorder never had this problem, the video
was
always fluid.
Best regards,
Dima

Im sure the manual will tell you if you read it, but I guess its a
low
light mode and it probably is indicated on the screen

Thanks for replying!
No, it's not the low light mode. I do not enable it and it is not
indicated on the screen.

You said panoramic is that a special wide mode, if its new take it
back, sony manuals are junk, and I found options even Sony support did
not even know that are not in my manual, that I could shoot stills
while taking video on an old unit. They have so much new stuff out its
hard to know all the operating parameters on every model. Keep looking
you will figure it out, but color slow shutter may be automatic and
its on with Night Shot on mine- Hide quoted text -

- Show quoted text -

Thanks Mark for replying!
Panoramic video means that you turn a camcorder around its axis during
recording.

snip

What?? If that is the actual function setting, it makes no sense at all to
have such a setting. You could do the same thing with any video camera.
Are
you sure it is not a wide screen setting?

Mike- Hide quoted text -

- Show quoted text -

Thank Mike for replying!
What "function setting" do you mean?
I meant panning shooting by a panoramic video.
I use wide lens angle usually during panning.

Oh, I understand what you mean now. Reading through this I thought you meant
there was a panoramic setting. Now I understand you are using a wide angle
lesnse and taking a panoramic shot.

Apprently you are not the only one having problems with this camera.
http://www.youtube.com/watch?v=Pv4b4wTrYr0]

If you just bougth it return it and get another to see if it has the same
problem.

Mike

 

[Michael Kennedy]

"D" <tarb@bk.ru> wrote in message
news:8176d4f2-bd92-4478-9f41-94c231ab1ec3@26g2000hsk.googlegroups.com...
On May 22, 11:19 am, "Michael Kennedy" <Mikek...@remthis.comcast.net>
wrote:

"D" <t...@bk.ru> wrote in message

news:1da0dd27-604a-47dc-a759-7635083f9b5d@c58g2000hsc.googlegroups.com...
On May 21, 6:18 pm, ransley <Mark_Rans...@yahoo.com> wrote:





On May 21, 7:02 am, D <t...@bk.ru> wrote:

On May 21, 3:54 pm, ransley <Mark_Rans...@yahoo.com> wrote:> On May
21,
5:30 am, D <t...@bk.ru> wrote:

Hello!
Why does a panoramic video (in an evening or inside a building,
shot
by Sony HC5E camcorder) look like the frame rate is about 10 fps?
My
11-year old JVC VHS-C camcorder never had this problem, the video
was
always fluid.
Best regards,
Dima

Im sure the manual will tell you if you read it, but I guess its a
low
light mode and it probably is indicated on the screen

Thanks for replying!
No, it's not the low light mode. I do not enable it and it is not
indicated on the screen.

You said panoramic is that a special wide mode, if its new take it
back, sony manuals are junk, and I found options even Sony support did
not even know that are not in my manual, that I could shoot stills
while taking video on an old unit. They have so much new stuff out its
hard to know all the operating parameters on every model. Keep looking
you will figure it out, but color slow shutter may be automatic and
its on with Night Shot on mine- Hide quoted text -

- Show quoted text -

Thanks Mark for replying!
Panoramic video means that you turn a camcorder around its axis during
recording.

snip

What?? If that is the actual function setting, it makes no sense at all to
have such a setting. You could do the same thing with any video camera.
Are
you sure it is not a wide screen setting?

Mike- Hide quoted text -

- Show quoted text -

Thank Mike for replying!
What "function setting" do you mean?
I meant panning shooting by a panoramic video.
I use wide lens angle usually during panning.

Oh, I understand what you mean now. Reading through this I thought you meant
there was a panoramic setting. Now I understand you are using a wide angle
lesnse and taking a panoramic shot.

Apprently you are not the only one having problems with this camera.
http://www.youtube.com/watch?v=Pv4b4wTrYr0]

If you just bougth it return it and get another to see if it has the same
problem.

Mike

 

[bz]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:483609C5.800054E9@hotmail.com:

bz wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote

Aluminium foil is a BAD idea. In the event that there is any
appreciable charge on a given pin, pushing it into aluminium foil
will discharge it *quickly* and the resulting current may kill it.

It is NOT the current that kills CMOS, it is high VOLTAGE that punches
holes in the insulating layers inside the chip. [I am not aware of ANY
chip families where tiny CURRENTS would be a hazard].

These are two different things.

Yes.

Those 'tiny' currents can be quite large
when discharging a significant charge.

Yes, but you can not 'have a significant charge' on a chip without having
a high voltage differential between the chip and the conductor! There are
not enough charge carriers to produce a high current from the small
internal capacitances of the cmos chip itself. If you have enough of a
differential between leads on the chip to cause a high current, then you
have already lost the chip due to the high voltage.

Enought to damage the chip's
internals through overcurrent.

NO! The danger to cmos from static electricity is not due to over-current,
it is due to high voltage differential between high impedance gates and
the base substrate of the cmos chip.

The voltage punches a hole in the insulating oxide layer.

TTL chips and the gated devices in ICs can be damaged by excess current
but that current is from a current source, not the kind of small static
charge that is developed when you carelessly handle a cmos chip.

The use of aluminum foil for storage of static sensitive components is
safe because there can not be an 'appreciable charge' on a given pin
without the device already having been destroyed by the voltage!

Do some calculations and see what kinds of voltage one would need to
produce enough coulombs of charge carriers to produce damage from
excessive current on any IC. Remember, you have only the volume of the
metal conductors involved to hold those charges.

Envision a capacitor, fully charged (the floating gate). Charge it to the
MAXIMUM voltage that it can stand. Now throw a DEAD SHORT across the leads
that feed that capacitor and look at the current flow as the cap
discharges.

Compare that current with the normal charge/discharge currents that flow
as pulses drive the gate when the IC is mounted and being used normally.
Look at the rise and fall times. Look at the conductor materials used on
the chip and connecting the chip to the lead. Find the weakest point along
the current path and compute the maximum peak current that can flow in
that conductor and for how long that current can flow before it causes
damage. [remember, current causes damage by heat.]

Now, check to see if the max permissible voltage could possibly produce
that current.

I think you will find that even chips that have built in weak conductors
['fuses' designed to be burned open by current flow] could not possibly be
damaged by the small charge allowable between any two pins of a CMOS
device.

Now, there MIGHT be some conditions where metal foil would NOT be a good
idea, like those where electrolysis could develop, but we are not
discussing those.

Another condition would be where there are high intensity ELECTRIC fields
nearby, STRONG Pulsed magnetic fields or RF fields nearby. [such as EMP]
But then the chip would be destroyed even if it were soldered into a
circuit.

I have worked with components that are VERY static sensitive (point
contact detector diodes used in radars) that were ALSO easy to damage with
excessive current.

We sometimes had RF fields around that could cause excessive current flow.
We kept the diodes wrapped in foil until we were installing them.

There are times when EM shielded rooms, anti-static mats and wrist straps
are not available. When they are not available, I work on a sheet of
aluminum foil and make sure I touch the foil and the component before the
component touches the foil.

--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+spr@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:483609C5.800054E9@hotmail.com:

bz wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote

Aluminium foil is a BAD idea. In the event that there is any
appreciable charge on a given pin, pushing it into aluminium foil
will discharge it *quickly* and the resulting current may kill it.

It is NOT the current that kills CMOS, it is high VOLTAGE that punches
holes in the insulating layers inside the chip. [I am not aware of ANY
chip families where tiny CURRENTS would be a hazard].

These are two different things.

Yes.

Those 'tiny' currents can be quite large
when discharging a significant charge.

Yes, but you can not 'have a significant charge' on a chip without having
a high voltage differential between the chip and the conductor! There are
not enough charge carriers to produce a high current from the small
internal capacitances of the cmos chip itself. If you have enough of a
differential between leads on the chip to cause a high current, then you
have already lost the chip due to the high voltage.

Enought to damage the chip's
internals through overcurrent.

NO! The danger to cmos from static electricity is not due to over-current,
it is due to high voltage differential between high impedance gates and
the base substrate of the cmos chip.

The voltage punches a hole in the insulating oxide layer.

TTL chips and the gated devices in ICs can be damaged by excess current
but that current is from a current source, not the kind of small static
charge that is developed when you carelessly handle a cmos chip.

The use of aluminum foil for storage of static sensitive components is
safe because there can not be an 'appreciable charge' on a given pin
without the device already having been destroyed by the voltage!

Do some calculations and see what kinds of voltage one would need to
produce enough coulombs of charge carriers to produce damage from
excessive current on any IC. Remember, you have only the volume of the
metal conductors involved to hold those charges.

Envision a capacitor, fully charged (the floating gate). Charge it to the
MAXIMUM voltage that it can stand. Now throw a DEAD SHORT across the leads
that feed that capacitor and look at the current flow as the cap
discharges.

Compare that current with the normal charge/discharge currents that flow
as pulses drive the gate when the IC is mounted and being used normally.
Look at the rise and fall times. Look at the conductor materials used on
the chip and connecting the chip to the lead. Find the weakest point along
the current path and compute the maximum peak current that can flow in
that conductor and for how long that current can flow before it causes
damage. [remember, current causes damage by heat.]

Now, check to see if the max permissible voltage could possibly produce
that current.

I think you will find that even chips that have built in weak conductors
['fuses' designed to be burned open by current flow] could not possibly be
damaged by the small charge allowable between any two pins of a CMOS
device.

Now, there MIGHT be some conditions where metal foil would NOT be a good
idea, like those where electrolysis could develop, but we are not
discussing those.

Another condition would be where there are high intensity ELECTRIC fields
nearby, STRONG Pulsed magnetic fields or RF fields nearby. [such as EMP]
But then the chip would be destroyed even if it were soldered into a
circuit.

I have worked with components that are VERY static sensitive (point
contact detector diodes used in radars) that were ALSO easy to damage with
excessive current.

We sometimes had RF fields around that could cause excessive current flow.
We kept the diodes wrapped in foil until we were installing them.

There are times when EM shielded rooms, anti-static mats and wrist straps
are not available. When they are not available, I work on a sheet of
aluminum foil and make sure I touch the foil and the component before the
component touches the foil.

--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+spr@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in
news:T_OdnXP8zMudsqvVnZ2dnUVZ_iydnZ2d@earthlink.com:

"ctops.legal" wrote:

On May 21, 11:34 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
"ctops.legal" wrote:
.....I get Spam in my Fax,
know anyway to stop that ?


Send it back to them, followed by 20 pages of black paper all taped
end to end. It uses up lots of their ink or toner and paper. When they
see what it costs them, they'll stop.

Report them to the FCC. Recently FAX spammers have been fined tens of
thousands of dollars.

You can also SUE the FAX spammer in small claims court.

Google for
fax spammer fined





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in
news:T_OdnXP8zMudsqvVnZ2dnUVZ_iydnZ2d@earthlink.com:

"ctops.legal" wrote:

On May 21, 11:34 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
"ctops.legal" wrote:
.....I get Spam in my Fax,
know anyway to stop that ?


Send it back to them, followed by 20 pages of black paper all taped
end to end. It uses up lots of their ink or toner and paper. When they
see what it costs them, they'll stop.

Report them to the FCC. Recently FAX spammers have been fined tens of
thousands of dollars.

You can also SUE the FAX spammer in small claims court.

Google for
fax spammer fined





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[dBc]

Greetings Bill..

The service manual & schematics aren't all that expensive to
purchase..

Something to consider. Personally, I don't hesitate picking up the
'official' schematics from the manufacturer. How much work they put
into them reveals whether I'll be interested in purchasing any future
products from that same manufacturer.

I had a Zenith 25" stereo color TV given to me that needed some
attention. The first thing I did was to find out who carried the
schematics and later, in fact, called Thompson and ordered them. For
the information I needed, they were worth every penny I spent. To this
day I don't regret purchasing those schematics!

Cheers,
Mr. Mentor



"billccm" <billccm@yahoo.com> wrote in message
news:909000d2-0527-45bf-80fc-c5cb0100d948@a1g2000hsb.googlegroups.com...
| Hello All:
|
| A coworker has an RCA rear projection TV that sizzled and shut down.
| If someone has a schematic they could forward, I would be grateful.
|
| Thanks for any help, and have a nice day,
|
| Bill