Grinder wrote:
> Previously I had come to alt.comp.hardware to seek speculation about the
> failure of a Gateway FPD1800 LCD monitor. The monitor was exhibiting a
> pronounced reduction in brightness, most noticeably at the top edge and
> diminishing down the screen. By the middle of the screen, brightness
> appeared to be normal.
>
> Paul was very helpful in suggesting that it might be the CCFL at the top
> edge of the panel that had failed. Opening the booger up and swapping
> the top and bottom lamps produced the same symptoms as before--a fade
> from the top towards the bottom. Perhaps it's my speculation alone, but
> that leads me to believe that it is the inverter, that drives the lamps,
> that has gone Wilbanks.
>
> I've taken that inverter out, and noticed something odd about it.
>
> http://home.mchsi.com/~grinder/temp/inverter-96.jpg
>
> The leftmost transformer (TM-008) appears to have vented. It doesn't
> show up so well in the picture, but the corner of the board adjacent to
> that transformer is globbed up with a crust that appears to have flowed
> from the transformer. The odd thing, though, is that transformer is
> closest to the connectors that feed the properly driven CCFLs. I cannot
> specifically tell if that transformer is for the adjacent lamps, but it
> makes ergonomic sense. At any rate:
>
> Q1) Is it worth trying to replace this transformer?
>
> I think my soldering skills are up to it, but are there realistic odds
> that this would cure my problem?
>
> Q2) Where can I get the replacement part?
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
> I've looked into getting the whole inverter, but have had no joy.
> InverterCentral.com reports a replacement part (KVBNKM045A) for an
> FPD1800, but that cannot be right--it's much too large to fit into the
> space provided. (Also, that company seems a little flaky. No one
> answers the live chat, and even though a toll-free number is often
> referred to on the site, there's none to be found.)
>
> The panel inside of the FPD1800 is an LG LM181E3 (A2). I've found a
> technical spec for that panel. It plainly states that "the inverter is
> an external unit to the LCD." I can find no markings on the inverter
> that suggests its maker or part number, other than a tiny sticker on the
> backside that has "0112" and "17324M" on it.
>

Maybe someone in sci.electronics group or related can offer some suggestions ?
I never was any good at tracing down transformers. The easy ones, are
ones with a brand name, like "Pulse". But stuff with just alphanumeric
strings, I wouldn't know where to start.

Web search:

Panel datasheet (looks like lamps and panel together are an assembly)
Panel has four lamps and four lamp connectors. Looks like maybe
one transformer on your inverter, drives two lamps ?

http://eio.com/lm181e3-a2.pdf

Replacement inverter, so they claim. But your picture of the
inverter, looks to have more pins on the tiny input connector
from the logic. While the high voltage side may be suitable for
your panel, the low voltage side may not have the same interface as
is used in your monitor. You'd have to check the pin counts on
the low voltage connectors and see if they are the same or not,
to see if this is even in the ballpark.

http://www.ergpower.com/pdf30/dmd42703.pdf

The same company offers a parts cross reference table:
http://www.ergpower.com/pdf30/cross.pdf

This doc has some comments on inverter operation.
It says those tiny caps near the output are an important
part of the circuit. The inverter operates in a constant
current mode, and the tiny caps near the connector are
part of the ballast. Since you have that "goo" near one cap,
maybe that is upsetting its tiny capacitance value.

http://www.ergpower.com/pdf30/confer.pdf

So while I don't have any really useful replacement info,
I'd try cleaning up that "goo" and see if things improve.
If the goo is not water-soluble, that cleanup may be
harder than it sounds. Since there is high voltage
in that region, you don't want to leave any
cleaning residue. Even something as trivial as dirt
underneath one of those HV caps, can arc over when
energized.

Paul