Question: I presume you have been in contact with L/G in Huntsville,
Alabama: Correct? They probably will be the ones you will need to get the
appropiate parts and information from to competently repair this item. IMHO
wrote in message
ups.com...
This can't stay on the back burner forever. This is also new technology
and with virtually no support from the manufacturer it is time to get
resourceful.

The reason that I was not there for the first try is no concern right
now. The light engine has been disassembled and reassembled and does
work. A burnt up plastic filter of some kind was removed and the big
splotch is gone from the center of the screen. The filter was red in
color, but was way too pale to be a significant color filter. The new
symptom was described to me incorrectly, and I was surprised because of
the normal competency of these guys, they said it had no red. It
must've been the source. Now that I have seen it I will describe it.

Originally the splotch was blue, and outside the splotch it was short
on blue, or had no blue. You could not see the pixels in the splotch.

Now after they removed the burnt up filter, it is not modulating the
blue. Everything black is blue, the blue screen comes up at turnon
before unblanking. Most of the highlights in the active video are
brownish, but in the menus it seems to be able to produce white on the
selected item. In the blue, which now shows pixels on the screen, in
the relatively white parts of the menu I can see the red, green and
blue pixels.

I have a good eye for color, there were some white parts, even though
it seemed like it couldn't produce white, it did in the menus. How is
this possible ? It looks as if you have an HK short in a weak blue gun,
but without retrace lines of course.

I strongly believe that the burnt up filter was a polarizing filter for
the blue channel. The red tint was only a tweak of the coloimetry.

Now I am almost sure I can come up with polarizing filters, but then
the problem becomes the orientation.

And this, I believe is the crux of the matter. I think what was removed
was a pre-polarizing filter. A refinement. Perhaps the tint was a
tweak, but then, it is possible it is not a polarizing filter. In that
case, the real polarizing filte, which has failed, is buried much
deeper in the light engine. This was a stick on filter, on a piece of
glass I am told. I have to consider the possibilty that this filter was
not the main proble, but a tertiary problem. That the people watched it
screwed up for a while. We acquired the set when it started saying
"Change lamp".

I simply don't think this is the only polarizing filter, if it even is
one.

What I intend to do is to put a polarizing filter there, screw the
tint. If the coloimetry is a little off, there are still many people
who would be happy with it. I believe it is worth persuing.

Something has actually occurred to me though recently. What if, with
the offending filter gone the light engine is fine ? What if the
problem is in the signal processing circuits and there is nothing wrong
with the LCDs at all ? I recite this point ; The menus produced white.
Not much, but some.

If it produced any at all it must be working somehow. An LCD element
requires both a pre and post polarizing filter to function.

The set reproduces red and green, and seems to able to kick up the blue
for highlighted menu items. This leads me to believe that maybe the
fault in the light engine is cured, and .......

You see the quandry.

Following through on my thinking, I cannot remember whther the menu was
able to make the blacks black instead of blue. Right now I think this
is the most important piece of information we need. If the menu
actually reproduces black, anywhere, the light engine is fine.

If that is the case the next thing is to feed it with Y-Cr-Cb, or some
component input. That would isolate it to the NTSC decoder or scan
convertor if it worked right then.

So, sorry for being so longwinded here, but I was trying to be as
complete and accurate as possible. Anybody out there knows anything
about LCD etc., am I on the right track ? You don't throw away
something that cost $3,000. And the whole set was $5,000 on average,
new
, and only a few years ago.

JURB