Toshiba TV29C90 problem; Image fades to black...

[Brad]

Hi Bob,

I should have said in my "update", I didn't list all the tests I
performed.

There is no coupling capacitor to the yoke in this TV.

For now, I put the "DOG" aside so I can work on other "stuff".

Brad

On Thu, 6 Nov 2008 18:05:56 -0800 (PST), in sci.electronics.repair you wrote:

On Nov 6, 8:20 am, bpet...@verizon.net (Brad) wrote:
Hi,

     Here is an update, but TV is not repaired yet:

     Note:  TV chassis is L03.1UAA and I have SM.

     The vertical deflection system uses discreet components.
There is no vertical amplifier IC,  which is common in all other TVs
I have worked on.  I replaced "2463" 100/50 and "2446" 470/16.
Both measured a loss of capacitance, but it made no improvement.
"2465" 10/160 tested very good, however I replaced it, but it didn't
fix the problem.

     I tested the two output transistors out of circuit (AOK).  I tested other
transistors in circuit.  Also tested various components in the vertical
deflection circuits.   Note: I originally checked solder joints and soldered
several joints that seem to lack good solder bond.

     I used a Yoke tester and checked both windings individually
after I separated the windings at a terminal.   Both windings read
"good", but one winding had a  higher reading than the other.  I
repeated the test incase of a poor test lead(s) connection, but the results
were the same!

    Scoping the two inputs to the vertical amp,  the "+drive" signal doesn't
match "-drive" waveform,  although it's "inverted".  The +drive signal is
"abnormal".
                                Brad



On Thu, 23 Oct 2008 11:42:33 GMT, Brad wrote:
Hi,

    I bought the service manual and found out that AN7225N is not the
vertical IC.

    If I repair this TV (in my spare time),  I will let everyone know what
part(s) caused this problem.

                    Brad

On Thu, 23 Oct 2008 11:42:33 GMT,  Brad wrote:

Hi,

  I have a Philips TV model 20PT6245/37 (mfg 05/05) in my
service shop with a loss of vertical deflection.  I do not have SM.

 For a moment after the TV is turned on, there is some vertical deflection,
but it collapsed into a single horizontal line in the middle.

  I checked solder joints at the vertical IC, resoldered them anyway, but
this had no effect.  Note: I soldered other joints too.  Flexing and tapping
on mother board has no effect.

  I couldn't find pin out info on the vertical IC   AN7225N on the
web so I could make additional tests.

             Thanks in advance,  Brad

 Before you type your password, credit card number, etc.,
be sure there is no active keystroke logger (spyware) in your PC.- Hide quoted text -

- Show quoted text -

If you have a scope, it and a dc voltmeter, you should be able to
check the voltages on the output transistors to make sure they are
biased correctly and then check the waveforms. If you don't see any
sawtooth at the output of the pair of output transistors, that's your
problem. If you do have a sawtooth there, then maybe the capactior
coupleing the output to the deflection coils is open/

Bob Hofmann

 

[Arfa Daily]

"Marshall Price" <d021317c@yahoo.com> wrote in message
news6mdnUr5pKWbSYzUnZ2dnUVZ_oLinZ2d@earthlink.com...

Arfa Daily wrote:
"Claude Hopper" <boobooililililil@roadrunner.com> wrote in message
news:K4KdnaQdINVA-mbVnZ2dnUVZ_trinZ2d@giganews.com...
I have been cutting power usage in my home. I have saved about 100 kwh a
month so far. I put power strips on all the vampire stuff like DVR, TV,
Stereo, DVD players, etc..

As I've commented on here before, you may come to regret that. Switch
mode power supplies do not like being fired from a cold start all the
time. They are designed these days with standby efficiency in mind, and
the manufacturers' choices of components, assume that they will be left
running continuously. Most either make use of a 'burst' mode that
actually results in a very low overall standby consumption, or have a
separate section which is just a tiny and very efficient standby supply.
Standby modes often also 'mask' important housekeeping tasks, as well as
being there to satisfy our fundamental laziness ...

Most 'secret' power consumption comes from much more power-hungry devices
than these, such as fridges, freezers, central heating pumps, and so on,
but here's a question for you. Since the power and gas utility companies
told us that the 30% hikes in the retail prices of their products were
due to the wholesale cost to them being based on the price of oil, now
that this has come back down to a 5 year low at around $62 a barrel, why
are the companies not now re-cutting our bills by 30% ? Either their
prices, and hence ours, *are* based on the price of oil, or they're not.
They can't have it both ways.

Arfa




I hope you haven't made the mistake of supposing a 30% increase to be
reversed by a 30% decrease. Consider: Increasing a dollar by 50% gives
$1.50. Decreasing $1.50 by 50% gives $0.75. (Also, 30% of a large number
is more than 30% of a small number.)

--
Marshall Price of Miami
Known to Yahoo as d021317c

Of course not. I am just as capable of doing simple math like this as anyone
else - it was just 'cleaner' to say 30% up - 30% down, although obviously
you are correct, and your point is taken. Just as a matter of interest,
contrary to what Jeff L believed in that once they had put the price up,
based on forward buying on long contracts, they could not then put it back
down again, this doesn't seem to be true. There has been a relatively sudden
drop in the price of car fuel at the pumps (in the uk) to a much more
reasonable - although still, in truth, excessive - figure per litre.
Likewise, my mother received a call from her utility provider last week, to
say that the cost of her gas and electricity was to come back down. Both of
these recent events are to be welcomed, and go to show that the oil
companies and utility providers really *can* put end user prices back down
if they really want to. That said, my point that they seem able to have all
of the logistics in place to increase prices overnight, but reckon that they
can't do the same in the opposite direction when the wholesale prices to
them come down, still stands.

Arfa

 

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On Sep 25, 3:15 pm, "james" <nos...@nospam.com> wrote:

I'm taking apart an old rear projection TV to get rid of it piece-wise.

There are some clear, odorless, liquid CRT coolant sealed on top of each
CRT. I accidentally spilled some inside the cabinet. What is the proper way
to dispose of these liquid?

According to one web site, it contains ethylene glycol and glycerine. Should
I mix it with with my car's old coolant and recycle it?

Dear James,

has any one given you right solution how to dispose of ethylene
glycole properly? I am also in search of proper recycling solution.

Please share me with the information if you had to
jason@torontorecycling.com. thank you.

 

[Leonard Caillouet]

<jasonlim@torontorecycling.com> wrote in message
news:b07d85b3-19df-4d5d-b160-dab3b24bcd74@n33g2000pri.googlegroups.com...
On Sep 25, 3:15 pm, "james" <nos...@nospam.com> wrote:

I'm taking apart an old rear projection TV to get rid of it piece-wise.

There are some clear, odorless, liquid CRT coolant sealed on top of each
CRT. I accidentally spilled some inside the cabinet. What is the proper
way
to dispose of these liquid?

According to one web site, it contains ethylene glycol and glycerine.
Should
I mix it with with my car's old coolant and recycle it?

Dear James,

has any one given you right solution how to dispose of ethylene
glycole properly? I am also in search of proper recycling solution.

Please share me with the information if you had to
jason@torontorecycling.com. thank you.


The proper recycling method depends on your location. Different government
agencies require different disposal. From a practical viewpoint, you can
safely dispose of it in any sanitary sewer system and it will be broken down
completely within days by the bacteria in the system. You could pour it on
the ground and the same thing would occur and other than the risk of
ingestion by animals it would cause no problems.

Leonard

 

[Meat Plow]

On Sun, 16 Nov 2008 16:36:10 -0800 (PST),
jasonlim@torontorecycling.comwrote:

On Sep 25, 3:15?pm, "james" <nos...@nospam.com> wrote:
I'm taking apart an old rear projection TV to get rid of it piece-wise.

There are some clear, odorless, liquid CRT coolant sealed on top of each
CRT. I accidentally spilled some inside the cabinet. What is the proper way
to dispose of these liquid?

According to one web site, it contains ethylene glycol and glycerine. Should
I mix it with with my car's old coolant and recycle it?

Dear James,

has any one given you right solution how to dispose of ethylene
glycole properly? I am also in search of proper recycling solution.

Mix with water and use as auto coolant.

 

Please visit our new online store at www.mercenarygraphix.com.
Wholesale pricing for quantity orders. Thanks and have a great day!

 

[Ismo Schmitt]

T.K.. No:9 -07. ongittua faktaa: 20% maailman sähköenergiasta tehty
vesivoimalla.

*Verrokiksi, että maailman energiasta on esim. ydinvoimin tehty vain ja
ainoastaan 2%.

Maailmassa on tällä hetkellä 45 000kpl suurpatoa, huolehtimassa ihmisten
kastelun ja vedentuotannon j a energian tarpeeesta. Vain noin 50%
vesienergiasta menee näin suoraan turbiineihin. Eli vesienergian t o d e l l
i n e n potentiaali lähentelee 40% maailman vesienergiatarpeesta.

*Maailmassa on esimerkiksi nyt teon alla yhä 1 500 suurpatohanketta.
Sanottaan verrokiksi, että esim. nyanssinen ydinenergia on pisarana j o p a
tässä meressä naurettavan pienellä 30 ydinasetehtaansa voimalla! Erot
korostuvat vielä siinä, että vesivoimaa on tehty jo massiivisesti
satavuosiluokassa. Kun ydinvoima kituttelee viimeisiä hiipuvia
energiapositiivisia kaivokasiaan vain ja ainoastaan 50v "askartelujensa"
tiimoilta.

*Jopa minulle oli suunnattoman suuri yllätys miten jopa varsin yleisesti
pienvoimalaitosenergiana esitelty vesivoima heittelee yhä vain näin
massiivisella dominanssilla maailman energialilliputin ydinvoiman yli. Ja
kun huomioidaan, että tuuli-vesi-, aurinko, geoterminen energia on ollut
markkinoilla vasta murto-osia ydionvoiman elinajasta oivalletaan, mille
uudisenergiapohjilleen maailman energiapaletti on vääjäämättä kääntymässä.

*Jaa niin tosiaan sitten bioenergian massiivinen tuleminen. Niinikään veden
kaltainen päästötön ja käytännössä merilevät ja metaaniklatraatit ja
vastaavat huomioiden rajattoman energian, ja viimeistään päästöttömän polton
ensivuoden tuotantoalku tulee k y l m ä s t i dominoimaan maailman 85%
polttoenergiamarkkinoita . Oikeastaan vain fossiilienergioilla on edes j o t
a i n vastaansanomisia tälle uusvanhalle sektorille. On jo nyt päivän
selvää, että 2008 Saksassa ja Ruotsissa valmistuvalle Suomessa 100%
uutispimennoissa pidetyllä, nyt jopa YK:n pyytämälle päästöttömälle poltolle
maailma tulee rakentumaan.

On selkeä totuus, ettei tällaisen potentiaalihyöyn edessä jollain
ydinnäpertelyllä ole m i n k ä ä n l a i s t a todellista potentiaalia, kuin
suorassa sotetappoteknikkaosionsa nyansseissa. Jos tästä nanorakin
esittämästä 27 maailman valtion esittämästä "ei ydinvoimin" toteutuvasta
energianhuollosta jotain voi kertoa, niin ydinvoimaan satsaa vain ja
ainoastaan menneisyyden maailma. Jolle ydinmustapekka jää korttipakasta
taatusti. On tietysti oikeus ja kohtuus, että se jää nimenomaan typerimin
toimineelle Suomelle! Mikään muu maa kun ei ole satsanut näin massiivisesti
menneisyyden monoteistiseen energianyanssiin.

;n;E;O;

 

[Eeyore]

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Graham

cross-posted to sci.electronics repair for info

 

[Eeyore]

Eeyore wrote:

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

That is REPLACE ALL OF THEM, NOT JUST ONES THAT HAVE BLOWN TODAY

You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Nice quip from the above

" From so many users, ranging from large corporate networks all the way
to the home user, the number one reason people give for wanting to
repair their hardware is they want to avoid a new system and the
disaster known as Windows Vista!

On a humorous note regarding Vista, I spoke to an IT guy who manages a
small business network for an insurance company (maintains a 100
terminal network), and had a bunch of failing Dell SX280's, which I
repaired. One branch had the brilliant idea to "upgrade" to Vista
systems, and his job was to make them all play nice with each other.
This gentleman was probably the most professional, polite, and courteous
clients I've ever spoken with on the phone, until we got onto the
subject of Vista....then the four-letter words started flowing
freely... In the end, he wiped all the Vista machines, and upgraded
them back to XP Pro."

Graham

 

[flipper]

On Mon, 24 Nov 2008 03:49:46 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

Eeyore wrote:

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

That is REPLACE ALL OF THEM, NOT JUST ONES THAT HAVE BLOWN TODAY


You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Nice quip from the above

" From so many users, ranging from large corporate networks all the way
to the home user, the number one reason people give for wanting to
repair their hardware is they want to avoid a new system and the
disaster known as Windows Vista!

On a humorous note regarding Vista, I spoke to an IT guy who manages a
small business network for an insurance company (maintains a 100
terminal network), and had a bunch of failing Dell SX280's, which I
repaired. One branch had the brilliant idea to "upgrade" to Vista
systems, and his job was to make them all play nice with each other.
This gentleman was probably the most professional, polite, and courteous
clients I've ever spoken with on the phone, until we got onto the
subject of Vista....then the four-letter words started flowing
freely...

ROTFLOL.

I know exactly how he feels.

Although, I start off already a bit 'excitable' so I have a head start
on the colorful language.

In the end, he wiped all the Vista machines, and upgraded
them back to XP Pro."

Graham

 

[Arfa Daily]

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:492A2208.4ACCA0F8@hotmail.com...

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

Arfa

You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Graham

cross-posted to sci.electronics repair for info

 

[f825_677]

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

 

[Eeyore]

f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every pin
and remove them individually. Then clean the holes up. It always wins on time and
cost.

Graham

 

[Eeyore]

Arfa Daily wrote:

"Eeyore" wrote
Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

True. They don't exactly go overboard on the drill diameter !

Graham

 

[Tom Del Rosso]

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:492A8D89.C6735563@hotmail.com

f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

 

[ian field]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:NuuWk.8598$mr6.2892@newsfe12.ams2...

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:492A2208.4ACCA0F8@hotmail.com...


Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a
board, that you will *ever* come across. And then some.

Arfa

They certainly can be difficult, an absolute must is an iron with sufficient
power to heat the joint through quickly (DO NOT use one of those soldering
guns that passes low voltage/high current through a solid copper element -
they induce destructive currents in the PCB traces!).

Usually the 2 wires can be eased out by tilting the capacitor as one of the
solder joints is melted and then the other until its out.

Clearing the holes also isn't easy, solder wick won't do it you need a
solder sucker and a lot of practice getting enough of the iron tip on the
tinned pad and still leave enough gap to suck the solder through - you will
probably have to go at it from both sides too!

Once or twice out of sheer desperation I've heated the through hole and
swatted the board on the edge of the bench to knock the solder out, but this
has a real risk of breaking any crystals on the board!

 

[ian field]

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:492A8D89.C6735563@hotmail.com...

f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle
to
do the job. These are some of the very worst bitches to get out of a
board,
that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every
pin
and remove them individually. Then clean the holes up. It always wins on
time and
cost.

Graham

If you make sure none of the pins are bent on the solder side sometimes its
possible to just lift the pins out one by one on the tip of the iron, if the
pin is sheared off close to the IC body it leaves a slight hook on top,
simply hook the tip of the iron under it and add fresh solder - this runs
down the pin providing heat transfer to the solder joint and the surface
tension holds the pin on the tip as you lift it out of the hole.

 

[Eeyore]

ian field wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote
f825_677 wrote:
Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle
to do the job. These are some of the very worst bitches to get out of a
board, that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every
pin and remove them individually. Then clean the holes up. It always wins on

time and cost.

If you make sure none of the pins are bent on the solder side sometimes its
possible to just lift the pins out one by one on the tip of the iron, if the
pin is sheared off close to the IC body it leaves a slight hook on top,
simply hook the tip of the iron under it and add fresh solder - this runs
down the pin providing heat transfer to the solder joint and the surface
tension holds the pin on the tip as you lift it out of the hole.

Goes to show what a range of real skills the true repairman needs. And yes I've
done it too. A magnetic Weller TCP tip and a pin containing steel helps !

Graham

 

[Eeyore]

Tom Del Rosso wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.

Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

Graham