green dots on plasma tv set

[Telespalla Bob]

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Ross Herbert]

On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
<leditapaolo.75@dalnasoalice.it> wrote:

:Hi, I have gained one LG based Plasma TV set.
:This TV is maked around model 42V5 chassis.
:In dark scenes, I see high quantity of green dots that is very numerous
:immediately after brightness change from light to dark, then decreases
:if scene persist dark.
:How I can check?
:Thanks and excuse me for my english.
:
:Bye.


Back a few years LG plasma 42 inch TV's suffered from a "green line" symptom.
Usually off to one side (can't remember which side) a thin vertical green line
stretched from top to bottom and as it worsened an additional parallel green
line would start to appear.

The only solution is a replacement of the plasma display.

I had an old war veteran friend who paid about $4000 for one of these sets and
he had owned it for about 2-1/2 years (long past the warranty period) when it
developed the symptom. After giving LG a good sob story they agreed to replace
the plasma screen at minimal cost (about $200). The real repair cost was well
over $1000, which he could definitely not afford. Repairing the set allowed him
to sell the set for $1000 but otherwise it was not worth a bean.

 

[Mark Zacharias]

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases if
scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!

Sounds like a Vs adjustment...

Mark Z.

 

[Telespalla Bob]

Mark Zacharias ha scritto:

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very
numerous immediately after brightness change from light to dark, then
decreases if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!



Sounds like a Vs adjustment...

Mark Z.

thanks, I try.
how I can adjust Vs? and how much voltage?
I have not schematics...

bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Telespalla Bob]

Ross Herbert ha scritto:

On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
leditapaolo.75@dalnasoalice.it> wrote:

:Hi, I have gained one LG based Plasma TV set.
:This TV is maked around model 42V5 chassis.
:In dark scenes, I see high quantity of green dots that is very numerous
:immediately after brightness change from light to dark, then decreases
:if scene persist dark.
:How I can check?
:Thanks and excuse me for my english.
:
:Bye.


Back a few years LG plasma 42 inch TV's suffered from a "green line" symptom.
Usually off to one side (can't remember which side) a thin vertical green line
stretched from top to bottom and as it worsened an additional parallel green
line would start to appear.

The only solution is a replacement of the plasma display.

I had an old war veteran friend who paid about $4000 for one of these sets and
he had owned it for about 2-1/2 years (long past the warranty period) when it
developed the symptom. After giving LG a good sob story they agreed to replace
the plasma screen at minimal cost (about $200). The real repair cost was well
over $1000, which he could definitely not afford. Repairing the set allowed him
to sell the set for $1000 but otherwise it was not worth a bean.

thanks, but I have green dots, not green line on my display.



--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Arfa Daily]

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in message
news:9ftxl.14175$8_3.4877@flpi147.ffdc.sbc.com...

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases if
scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!



Sounds like a Vs adjustment...

Mark Z.

Seconded ...

Arfa

 

[Mark Zacharias]

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c6767c$0$1110$4fafbaef@reader2.news.tin.it...

Mark Zacharias ha scritto:
"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!



Sounds like a Vs adjustment...

Mark Z.

thanks, I try.
how I can adjust Vs? and how much voltage?
I have not schematics...

bye.


--
Prima di rispondermi devi togliere le dita dal naso!!!

Usually just below 200 volts; adjust to lower the voltage until the speckes
disappear. If no change, return the adjustment to it's original position.

Just exactly where this is located in your unit I don't know. In Samsung
models it is usually in one corner of the Y main board, near a Vs test
point.


Mark Z.

 

[Franc Zabkar]

On Sun, 22 Mar 2009 11:05:07 -0500, "Mark Zacharias"
<mark_zacharias@labolgcbs.net> put finger to keyboard and composed:

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases if
scene persist dark.
How I can check?

Sounds like a Vs adjustment...

Mark Z.

Ditto.

The Serviceman column in the April 2009 issue of Silicon Chip Magazine
identifies the problem as a V Setup adjustment. FWIW, on the
PDP42V72462 chassis it is VR1 on the Y Sus board.

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

 

[Telespalla Bob]

Franc Zabkar ha scritto:

On Sun, 22 Mar 2009 11:05:07 -0500, "Mark Zacharias"
mark_zacharias@labolgcbs.net> put finger to keyboard and composed:

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases if
scene persist dark.
How I can check?

Sounds like a Vs adjustment...

Mark Z.

Ditto.

The Serviceman column in the April 2009 issue of Silicon Chip Magazine
identifies the problem as a V Setup adjustment. FWIW, on the
PDP42V72462 chassis it is VR1 on the Y Sus board.

- Franc Zabkar

Thanks to all.
If Vs and VR1 adjustment does not solve the problem, is it possible that
this is an electrolytic capacitor failure?

Thansk.


--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Arfa Daily]

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49cbcf78$0$1116$4fafbaef@reader3.news.tin.it...

Franc Zabkar ha scritto:
On Sun, 22 Mar 2009 11:05:07 -0500, "Mark Zacharias"
mark_zacharias@labolgcbs.net> put finger to keyboard and composed:

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?

Sounds like a Vs adjustment...

Mark Z.

Ditto.

The Serviceman column in the April 2009 issue of Silicon Chip Magazine
identifies the problem as a V Setup adjustment. FWIW, on the
PDP42V72462 chassis it is VR1 on the Y Sus board.

- Franc Zabkar


Thanks to all.
If Vs and VR1 adjustment does not solve the problem, is it possible that
this is an electrolytic capacitor failure?

Thansk.

Anything's *possible* I suppose, but in this case, I would say that it's
pretty unlkely. The symptoms you describe are very typical of mis-adjustment
of Vs, and I would give correcting that, a better than 90% chance of success
....

Arfa

--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Telespalla Bob]

Arfa Daily ha scritto:

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49cbcf78$0$1116$4fafbaef@reader3.news.tin.it...
Franc Zabkar ha scritto:
On Sun, 22 Mar 2009 11:05:07 -0500, "Mark Zacharias"
mark_zacharias@labolgcbs.net> put finger to keyboard and composed:

"Telespalla Bob" <leditapaolo.75@dalnasoalice.it> wrote in message
news:49c5783a$0$1111$4fafbaef@reader3.news.tin.it...
Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Sounds like a Vs adjustment...

Mark Z.
Ditto.

The Serviceman column in the April 2009 issue of Silicon Chip Magazine
identifies the problem as a V Setup adjustment. FWIW, on the
PDP42V72462 chassis it is VR1 on the Y Sus board.

- Franc Zabkar

Thanks to all.
If Vs and VR1 adjustment does not solve the problem, is it possible that
this is an electrolytic capacitor failure?

Thansk.


Anything's *possible* I suppose, but in this case, I would say that it's
pretty unlkely. The symptoms you describe are very typical of mis-adjustment
of Vs, and I would give correcting that, a better than 90% chance of success
...

Arfa
--
Prima di rispondermi devi togliere le dita dal naso!!!

I have tryed to adjust Vs.
In back of panel there it is a label that says: Vs=190V

I tried up to 195V but green dots does not disappears.
I also tried to adjust under 180V, and green dots decreases, but
together with screen brightness and detail...

If not capacitors, how I can try?

Thanks.




--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Meat Plow]

On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
<leditapaolo.75@dalnasoalice.it>wrote:

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.

Probably the PDP not erasing the pixels fast enough. If this is the
case the only way to repair is to replace the PDP.

This set is made by Hyundai.

 

[Mark Zacharias]

"Meat Plow" <meat@petitmorte.net> wrote in message
news:2mftsq.nb1.19.2@news.alt.net...

On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
leditapaolo.75@dalnasoalice.it>wrote:

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.

Probably the PDP not erasing the pixels fast enough. If this is the
case the only way to repair is to replace the PDP.

This set is made by Hyundai.

I agree at this point - an aged panel.

Mark Z.

 

[Arfa Daily]

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in message
news:ftdzl.22198$c45.12527@nlpi065.nbdc.sbc.com...

"Meat Plow" <meat@petitmorte.net> wrote in message
news:2mftsq.nb1.19.2@news.alt.net...
On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
leditapaolo.75@dalnasoalice.it>wrote:

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.

Probably the PDP not erasing the pixels fast enough. If this is the
case the only way to repair is to replace the PDP.

This set is made by Hyundai.


I agree at this point - an aged panel.

Mark Z.

Agreed also. The clue is probably that it gets better as Vs is turned down,
but not before the picture starts to deteriorate ...

Arfa

 

[Telespalla Bob]

Arfa Daily ha scritto:

"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in message
news:ftdzl.22198$c45.12527@nlpi065.nbdc.sbc.com...
"Meat Plow" <meat@petitmorte.net> wrote in message
news:2mftsq.nb1.19.2@news.alt.net...
On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
leditapaolo.75@dalnasoalice.it>wrote:

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.
Probably the PDP not erasing the pixels fast enough. If this is the
case the only way to repair is to replace the PDP.

This set is made by Hyundai.

I agree at this point - an aged panel.

Mark Z.

Agreed also. The clue is probably that it gets better as Vs is turned down,
but not before the picture starts to deteriorate ...

Arfa

yes, picture panel has several work hours, but I not remember that green
pixels was already present before IPM fail.
This is a common defect due to aging? (I never put hands in plasma tv set)
I have checked ripples to Vs line with oscilloscope ac coupled, and I
see most spikes (about 3-4Vpp)... for this thought about the capacitors.

conclusions?

Thanks.


--
Prima di rispondermi devi togliere le dita dal naso!!!

 

[Meat Plow]

On Sat, 28 Mar 2009 19:01:31 +0100, Telespalla Bob
<leditapaolo.75@dalnasoalice.it>wrote:

Arfa Daily ha scritto:
"Mark Zacharias" <mark_zacharias@labolgcbs.net> wrote in message
news:ftdzl.22198$c45.12527@nlpi065.nbdc.sbc.com...
"Meat Plow" <meat@petitmorte.net> wrote in message
news:2mftsq.nb1.19.2@news.alt.net...
On Sun, 22 Mar 2009 00:29:36 +0100, Telespalla Bob
leditapaolo.75@dalnasoalice.it>wrote:

Hi, I have gained one LG based Plasma TV set.
This TV is maked around model 42V5 chassis.
In dark scenes, I see high quantity of green dots that is very numerous
immediately after brightness change from light to dark, then decreases
if scene persist dark.
How I can check?
Thanks and excuse me for my english.

Bye.
Probably the PDP not erasing the pixels fast enough. If this is the
case the only way to repair is to replace the PDP.

This set is made by Hyundai.

I agree at this point - an aged panel.

Mark Z.

Agreed also. The clue is probably that it gets better as Vs is turned down,
but not before the picture starts to deteriorate ...

Arfa




yes, picture panel has several work hours, but I not remember that green
pixels was already present before IPM fail.

Too bad you don't remember, this would help immensely.

This is a common defect due to aging? (I never put hands in plasma tv set)
I have checked ripples to Vs line with oscilloscope ac coupled, and I
see most spikes (about 3-4Vpp)... for this thought about the capacitors.

conclusions?

Thanks.

My conclusion is this is a classic case of an aged panel in need of
replacement. You might want to research how plasma develops an image
to give you a better understanding of how age affects the process.
I doubt that 3-4Vpp noise in the Vs is responsible but I could be
wrong and would be happy if I were wrong given the cost of a new PDP.
If time is not a factor you could ESR some capacitors in the Vs and
try to eliminate the ripple.