I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. Clearly the VGA input is
being incorrectly processed. Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

pedro wrote:
I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. Clearly the VGA input is
being incorrectly processed. Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

Some LCD monitors have colour temperature settings embedded somewhere in
their menu system. I can certainly get my Philips monitor to emulate the
behaviour you describe.

Sylvia.

Meat Plow wrote:
On Sun, 27 Dec 2009 09:57:11 +0800, pedro wrote:


I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. Clearly the VGA input is
being incorrectly processed. Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.


Maybe something you did while servicing? I wouldn't look for faulty
caps in the smps to cause anything but a fail of the smps.
I know some one that handed me a power supply board from a LCD TV that
needed a cap replaced. This was a known problem with this unit.
I had to order the cap because of it's size..

I replaced the cap, and then handed the board back to the owner...

He put it in and while doing so, pinched the small mylar ribbon going
to the LCD panel it self.

End of story.

The cost of getting a replacement ribbon and what was already put
in was more than a new TV. This was a small unit..

The morrow of the story is, while trying to recover home entertainment
equipment that is valued very close to a repair job, is gambling!

You some times lose!

Meat Plow Inscribed thus:

On Sun, 27 Dec 2009 09:57:11 +0800, pedro wrote:

I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. Clearly the VGA input is
being incorrectly processed. Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

Maybe something you did while servicing? I wouldn't look for faulty
caps in the smps to cause anything but a fail of the smps.

A possible cause is the user settings got cleared in the flash chip
whilst replacing components.

--
Best Regards:
Baron.

snip


was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

Maybe something you did while servicing? I wouldn't look for faulty
caps in the smps to cause anything but a fail of the smps.

For the most part, I would agree with that, but I have had a few cases of
cheapo DVD players, where a bulging secondary side cap, has caused the rail
which is used as the regulation reference (often the 5V) to drop, which has
resulted in the supply trying to compensate by widening the drive pulses,
which has in turn resulted in the 12V rail rising, which has then led to
other circuitry getting ****ted ...

Arfa

On Sun, 27 Dec 2009 09:57:11 +0800, pedro wrote:

I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. Clearly the VGA input is
being incorrectly processed. Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

Followup: Thanks to all for the comments. While there is a certain
amount of adjustment available, it isn't enough to remove the pink
tinge completely. Given that whites show as white from the test/menu,
I stick with my view that VGA signal processing is shot. Whether the
video board took a hit from the SMPS failure I won't know until
another Samsung 740/940 crosses the bench, when I'll swap the boards.

On Dec 26 2009, 5:57*pm, pedro wrote:
I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). *Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. *Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. *Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. *Clearly the VGA input is
being incorrectly processed. *Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? *Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

It's set to component and getting RGB or vice versa.

G²

On Tue, 12 Jan 2010 20:45:45 -0800 (PST), wrote:

On Dec 26 2009, 5:57*pm, pedro wrote:
I normally repair LCD monitors which are heading for landfill, and
they are turned over to needy/worthy groups (usually replacing olde
CRTs). *Almost always, repairs are either "recap SMPS" or "replace
inverter transistors", and the hardest part is getting the case apart.

Recently one Samsung 943NWX - presented as "dead" - had an odd
outcome. *Replaced the bulging electros in the PSU and the unit came
to life, but with a dominant pink tinge to the entire screen area.
Normally I would ascribe this to backlight end-of-life, but three
things contradict this diagnosis. *Firstly, hitting the menu button
with no video drive gives a small display "Test OK" (or similar) text
on a background which is white, so backlight colouration is unlikely.
Ditto if the menu system is fired up when a video signal is present -
pink screen but the menu b/g is pure white. *Clearly the VGA input is
being incorrectly processed. *Finally, the donor has confirmed that it
was white before failure.

Has anyone experienced the video processor taking a hit when the SMPS
goes west with faulty caps? *Clearly the unit doesn't warrant pursuing
a video chip replacement, and thereare no signs of distress on the
video board.

It's set to component and getting RGB or vice versa.

If I understand you proposition correctly, then no - it only has VGA
input capability.

Try to fiddle a bit the VGA connector and try another cable / source.
Most of the times one of the color signals does not contact fully,
sometimes due to the connectors getting old or some bad solder joint.

On 12 Gen, 14:49, pedro wrote:
Followup: *Thanks to all for the comments. *While there is a certain
amount of adjustment available, it isn't enough to remove the pink
tinge completely. *Given that whites show as white from the test/menu,
I stick with my view that VGA signal processing is shot. *Whether the
video board took a hit from the SMPS failure I won't know until
another Samsung 740/940 crosses the bench, when I'll swap the boards.- Amaga el text entre cometes -

On Thu, 14 Jan 2010 14:46:29 -0800 (PST), Jeroni Paul
wrote:

Try to fiddle a bit the VGA connector and try another cable / source.
Most of the times one of the color signals does not contact fully,
sometimes due to the connectors getting old or some bad solder joint.

On 12 Gen, 14:49, pedro wrote:
Followup: *Thanks to all for the comments. *While there is a certain
amount of adjustment available, it isn't enough to remove the pink
tinge completely. *Given that whites show as white from the test/menu,
I stick with my view that VGA signal processing is shot. *Whether the
video board took a hit from the SMPS failure I won't know until
another Samsung 740/940 crosses the bench, when I'll swap the boards.- Amaga el text entre cometes -

That was all checked out as soon as the pink tinge became evident.
Also checked compponents on the video board for any signs of distress
or dry joints, and finger probing as well.