Zenith D60WLCD

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

Reply to
ZZactly
Loading thread data ...

Reply to
Papa_J

No, no need. They will be happy to sell a $3,000 new light engine.

When I said it was time to get resourceful I meant it. That should explain why I posted. If my assumption the this pale red piece of plastic is a prepolarizing filter the issue becomes how to orient the replacement.

So many people are used to going to the manufacturer, and if it was worth it I would. I would even pay them $40 or so for a fifteen cent piece of polarized plastic, but it's $3,000. I have no intention of contacting them, I can source polarizing filters.

To give to an idea, we just bought a $4,000 truck for $350. Needs a tranny. No it does not. I am not going to GM for a tranny, or for the gear therein. (5 speed manual, no reverse). I'm going to the transmission people, not the OEM of the truck.

"We" have been doing things like this all our lives, but the LCD projection thing is so much more involved I was hoping that someone out there knows something.

I can probably shine light through the panel and determine the polarization, maybe. I can assume that being unpowered the pixels are in the untwisted state. Do I assume this is black, or white ? (blue)

Gotta understand what I do. We the unknowing, led by the unwilling can do so much with so little, that I have gotten to the point where I make more than the boss. I do so much without any help from the manufacturer that I simply do not consider it an option anymore.

When we get into this transmission we will not be buying tool J113456798 and J877543, I have a lathe and can make the dummy shafts so that during disassembly the cluster doesn't fall all over the floor.

Even if this Zenith needs a dichroic mirror, I will find a place that makes them. I already have. And lemme tellya, I might be able to get it for free. The trick there is not to tell them you are repairing something that is already built, you gently lead them to believe you are an OEM building a prototype. They will send free "samples". My Mom taught me that.

The way the manufacturers treat ISCs I am used to it. I used to work for an ASC and I couldn't stand it anymore. The support was there, but that didn't help the build to be any more servicer friendly.

Look at what these manufacturers do, and you think they're your friend ? Ha. They indeed have the upper hand, but I have been the underdog all my life, and I have prevailed. As I ask for help, I also share information.

No sir, I have no intention of contacting LG, by the time I sit on hold for two hours the shop has lost hundreds of dollars. Then I will find out what I already know, replace the light engine to the tune of $3,000.

The interests of manufacturers and servicers are diametrically opposed. There is no anger involved, they operate in their best interests. Well, buddy, so do I. I will not, however, feel sorry for them when they can't sell another TV for $5,000 that only lasts two years.

JURB

Reply to
ZZactly

You should try an Email/Fax Campaign, to the Source of Mfg LG in Korea/or wherever it comes from. A Courteous inquiry to the orient will often get results. Like how pleased you are with the Quality and innovations of LG, etc, and how yours has this small minor Red Filter problem you are trying to remedy. You want to restore the wonderful picture you used to have. You have been unable to get good results from LG Huntsville etc. Go on and on, etc. I once did this with My Dads mazda rotary, and later with my 626 head gasket problem. I got a $800 refund direct from Mazda for my efforts.

Reply to
lakewood

Reply to
Art

My concern is as they sell more and more of these things, they will go to TV shops for repair when they break doown. This is the future, at least for awhile. Then DLPs might prevail.

The reason I avoid going to the manufacturer, even overseas is that two days from now they might be gone.

When I get my thinking cap pointed again in the direction of this problem, I want viable solutions that do not include the manufacturer. It is the only way. If we're the only shop in the country that can fix this shit, great, we'll lock the front door and make money.

Commonalities exist in ALL LCD projectors, and after dichroic mirrors and polarizing filters are sourced, there is potential.

As long as the LCD panels are good, it is smoke (removal thereof) and mirrors. I'm sure Apex is going to build LCD projos eventually, what kind of luck do you think I'll have with them ? I have worked on an Apex tri-CRT based RPTV and let me tell you, in unservicabiliy they take the cake. They make a Samsung look easy. I actually fixed the set, but later found some sort of initialization problem. We also had a Tantus in that would every once in a while come on with an upside down picture.

This shit is getting harder and harder, we need an edge. If we don't get that edge, I will be running a business doing home improvement. Remember "Other People's Money", no matter how large our market share is of a dying market, it is dead. Problem is now, even liquidating a TV shop is hard. You have a hard time getting out with any decent money to start something else.

I can get polarizing filters, the question is, is the light still polarized coming out of the lens ? If so, the screen might depolarize it, or not. If you look at an LCD RPTV with polaroid glasses on, does it disappear at certain angles ? I think if you diffuse light, like the screen does, it will no longer be polarized. But then I can get in between the lens and screen to determine the polarization, thing is I don't know if it is possible. Not being at a focal point might screw it up.

I have studied up on the operation of LCDs. There are just some things I do not know.

Yet.

JURB

PS, thanks for the replies, but really, they are not going to sell me that piece of plastic, the set is a couple years old and I really think that they simply won't be stocking that part. Why would they ?

JURB

Reply to
ZZactly

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.