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!