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Hitachi 50" DLP Rear Projection TV - Help with Blue Dots/Fog

Thread starter #1
Hello, I hope this note finds you well!

I am looking for help with polarizing filter part(s) to fix my Hitachi 50" rear projection TV and your assistance with a source who sells polarizing filters (glass rectangles, I presume) to the public. Any instructional videos would also be helpful as well as tips for a first time DIY repair. I am confident in my repair abilities and just need the part and instructions on the install.

The TV is from 2006 and has served well to date, except for the blue dots and fog issue. On the back of my TV are the following numbers:

Hitachi Nomtype: LP600

MODEL # 50VS69A

177W, 2.8A

Manufactured August 2006

Avg power A.C. 171W

120v 60Hz

Chassis model: LC67

The issue is there is a lot of blue fog and a constellation of blue dots on the screen that is distracting to look at. The unit is out of warranty--about 12 years old. I am looking to repair it myself (DIY).

My research says that the blue dots might be a light engine issue/optical block problem, but there is a way to change out one (or more) of the colored polarizing filters inside the unit inexpensively. Do you know which color polarizing filter I need that would correct the blue dots/blue fog issue? I can't afford a new light engine given what I hear they cost ($500+), but the filter (~$30?) could be a good workaround.

I would be most appreciative of any help you can offer regarding this blue fog issue. Again, what color filter is causing the blue fog (I haven't opened the TV yet), who sells the replacement filters directly to the public, and do you have instructions on a first time repair attempt?

Here are two pictures of the TV and the blue dots/fog:

hitachi1.jpg

hitachi2.jpg
 
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unclejed613

Well-Known Member
#2
unless you find somewhere that has a bunch of scrapped TVs for parts, you're probably out of luck. DLP was phased out more than 10 years ago, and the longest any manufacturer might stock replacement parts is 5-7 years, but the average time parts are stocked these days is the warranty period plus one or two years, with things only remaining in stock after warranty as they get used.
 

gophert

Active Member
#3
2
unless you find somewhere that has a bunch of scrapped TVs for parts, you're probably out of luck. DLP was phased out more than 10 years ago, and the longest any manufacturer might stock replacement parts is 5-7 years, but the average time parts are stocked these days is the warranty period plus one or two years, with things only remaining in stock after warranty as they get used.
I your comments about availability of repair parts may not be are completely true. Samsung and LG's outlets just offer a replacement Tv. Costco told us that no warranty parts are available - on a model hat was still in stores.

Also, DLP technology is definitely finding a new life in Heads Up displays (automotive) and nano-projectors - not projector TVs.
 
Thread starter #4
Thanks for the information, guys. I didn't know about the display technology still being viable for other uses. I appreciate your taking the time to respond. :)

Since I can't find any spare junk projectors, and the parts aren't being manufactured any longer, might you have any idea if a burnt blue LCD panel in this projector television can be opened and repaired or rebuilt myself? I don't have an exact picture of the LCD panel from my Hitachi unit, but here is a similar example from an Epson TV unit from the web:

panel.jpg

I currently have my Hitachi light engine disassembled (actual picture below), but I have to figure out how to get the printed circuit board off and get underneath it to take the LCD panels out (called the optical block?) and the polarizing filters. I will post pictures when I get to that part.

It seems like this issue is something that could almost be repaired inexpensively with 3-D filter glasses cut to size from the movie theater (but with high heat resistant glass, not plastic lenses) rather than replace the whole (now obsolete) light engine.

Does anyone know of any suppliers, companies, or individuals who could supply or fix the LCD panel glass and cut me some blue polarizer glass to fit the frame of the old, burnt blue polarizing filter? I can take it out and measure it. I have tried writing Lampdeng, a company in China that someone else had success with, but I haven't heard back from them. Thanks in advance!

hitachi_light_engine.jpg
 
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rjenkinsgb

Active Member
#5
DLP and LCD are two very different technologies.

DLP uses an array of microscopic mirrors, each with its own actuator; the optics are in effect mechanical.
https://www.listeningpost.co.nz/assets/dmd_chip_125623_1.jpg

Colour typically uses either a rotating colour wheel, with an image illuminated sequentially as each filter is in line with the optics, or three DLP modules with individual R, G, B light sources & the images combined via prisms / mirrors.

If it's purely a colour filter that's damaged, can you use one from a different make?
eg.
https://www.ebay.co.uk/itm/Toshiba-Color-Wheel-56HMX195-Tested-and-Working/122940867084
https://www.ebay.co.uk/itm/OEM-Orig...er-Nec-Optoma-Hitachi-Projectors/201684551394
 
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gophert

Active Member
#6
I would stop working on this old TV immediately - especially if you expect any out-of-pocket expenses.

A new basic Samsung 55" TV will cost $300.

I suggest a basic TV because it has all the features of your current TV and more!
- HD resolution 1080p vs 720p for your hitachi
- No bulb to replace every so often ($50 or more each)
- Uses less than 1/3 the power.
- Much brighter image
- Smart TV features available on this TV but a much faster processor is recommended if you want to watch streaming video - spend $50 to $100 more for a decent Smart TV.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
#7
I would stop working on this old TV immediately - especially if you expect any out-of-pocket expenses.
I would agree, projection sets were pretty crap anyway, and DLP ones probably worse than most.

Smart TV features available on this TV but a much faster processor is recommended if you want to watch streaming video - spend $50 to $100 more for a decent Smart TV.
Or simply buy a Firestick, which is far 'smarter' than any TV you can buy - smart TV's aren't particularly 'smart', and soon begin to lose what features they came with anyway.
 

unclejed613

Well-Known Member
#8
Or simply buy a Firestick, which is far 'smarter' than any TV you can buy - smart TV's aren't particularly 'smart', and soon begin to lose what features they came with anyway.
a good compromise would be to get a TV, not necessarily a smart one, and a current model blu-ray player. blu-ray players have the same "smart" features that smart TVs have. replacing a blu-ray player is less expensive than replacing a TV.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
#9
a good compromise would be to get a TV, not necessarily a smart one, and a current model blu-ray player. blu-ray players have the same "smart" features that smart TVs have. replacing a blu-ray player is less expensive than replacing a TV.
Except BD Players are as dumb as TV's, it's a lot easier to get a far 'smarter' Firestick which is much cheaper to replace, if it even becomes necessary as such devices are much better at getting regular updates.
 

gophert

Active Member
#10
Except BD Players are as dumb as TV's, it's a lot easier to get a far 'smarter' Firestick which is much cheaper to replace, if it even becomes necessary as such devices are much better at getting regular updates.
And they are now on sale - $24 each or 2 for $39 for 1080p device. Voice control is great - no need to try to enter test with a remote controller.
Normally $49 each. 4K devices are $39. What a bargain.

All of our early smart TV has a slow processors and need to buffer occasionally. No lag/buffering with fire stick.
 
Thread starter #11
Hi, guys. Thank you for all your replies. I'll reply to each individually and then offer some general updates and questions.

rjenkinsgb - I'm still not sure whether my Hitachi TV uses DLP or LCD technology. I was always under the impression my TV uses DLP--if the blue panel actually uses highly specialized micromirror DLP technology, I would imagine rebuilding it would be out of the question/impractical. Inside the unit are 3 colored red, green, and blue LCD panels. Below is my optical block:

3 panels optical block.JPG

Each LCD panel has a different colored polarizing glass filter contained in a metal frame in front. I disassembled the unit further and found a blob on the blue LCD panel when held up to the light and major burn in on a "red" colored polarizing filter in front of the blue panel. The other two filters (for the red and green LCD panels) look fine. I disassembled most of the light engine and I did not find a color wheel inside, if that helps.

gophert - I didn't know the new 55" with those specs were so affordable; I spent $900 at Circuit City (RIP) on my Hitachi back in the day. I checked and saw some good Black Friday/Cyber Monday deals on these Class 4K Ultra HD 2160P LED TVs in the $300 price range on sale. Any idea how long an LED TV like this is "projected" (lol) to last?

While it sounds practical to stop working on the TV and buy a newer model for time and expense, I still want to try and fix it for my own knowledge (first time doing this repair) and because I really like this old TV--I've taken good care of it for 10+ years, only had one bulb replacement in that time, and it feels like such a waste to scrap it and throw it out curbside. I'm thinking I will either keep it as a spare and deal with the blue fog or be patient in the hopes of locating someone who might have the parts I am looking for to fix this baby up. Practically, when I put the TV back together, I am expecting that the picture and colors don't have to be factory perfect, just something better than what I have currently and something that will get rid of the blue dots/blue fog.

Nigel Goodwin & unclejed613 - Thanks for the suggestions for smart features re: Firesticks or Blu-ray equipment. I am not really looking for smart features, being a more retro kind of guy, but I am interested in having some composite (red, white, yellow) and/or component (red, green blue) video ports for my older video game hardware (SNES, Gamecube, PS2, etc.) and DVD/VHS players. My Hitachi has at least 5 of these inputs, IIRC. I see a lot of the newer big screen TVs only have HDMI ports. I am thinking HDMI to composite or HDMI to component adapters probably exist to plug in these older consoles. Any suggestions?


Anyway, onto general updates and pictures:

As mentioned, the blue LCD panel has a circular blob in it (hard to see), contributing to the bad picture:

blob.JPG

For the polarizing filter, I measured the plastic/glass in millimeters. It measures for the outer glass 26mm x 21mm, and the inner glass (the red tinted part) 22mm x 18mm. See pics below. A company in China called Lampdeng offers new polarizing filters, and helped someone else with this problem on the web, but I haven't been able to get in touch with Lampdeng. Is there anywhere else I can find a replacement or a scrap red colored filter for the blue LCD panel? I am assuming it has to be red in color. Here are pics:

burnt polarizer in front of LCD panel.JPG blue LCD and polarizer measurements 1.JPG blue LCD and polarizer measurements 2.JPG blue LCD and polarizer measurements 3.JPG

Lastly, I did find someone on eBay is selling this optical block from a Hitachi 50V715 he disassembled:

https://www.ebay.com/itm/Hitachi-50...h=item3d31645db5:g:becAAOSwA3dYh5yt:rk:3:pf:0

He sent me a close up picture of his blue LCD panel. Here it is, as compared to my blue LCD panel:

My panel: my bad blue panel and numbers.JPG His panel: replacement blue panel and numbers.jpg

Does anyone know if this Hitachi 50V715 blue LCD panel would be compatible with the main electronics board on my Hitachi 50VS69A projector (I noticed there are the same 36 pins on the ribbon cable, and most of the numbers on the cable are the same)? It's the closest match I have found. It would be great if it worked. I asked the seller, who said that, honestly, he does not know if it is compatible or not, as it has been some time since he has had to service Hitachi TVs and he does not know if they are compatible from one model to another.

Whoa, sorry for writing a book there. I will look forward to hearing your thoughts on this. :)

Cheers!
 
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#12
OK, that's LCD not DLP.
It uses separate LCD modules for each colour with fixed filters, so no colour wheel.

The spare LCD in the photo is probably compatible; the main number is the same, at a guess the second section is a revision number - yours is G00 and the spare looks like its G01 ?

Re. the colour wheels on ebay, I was thinking that if it did use fixed filters for colour separation, the segments of one of those may be suitable material for repairing the old burnt ones.


Re. the life of LED screen TVs; generally on average on TVs from major manufacturers (and random early failures aside) I'd expect ten to twenty years or possibly more.
LED screen are just LCD panels with LED backlights rather than the original cold cathode tubes fluorescent tubes in previous LCD screens. They are well tested technology.

OLED (in any of it's several name variants) is a totally different thing and not yet well proven in large-screen displays like TVs.

That uses LEDs directly as the colour emitters in each pixel, which in theory gives better contrast and response - but the existing technology appears to suffer from a fading effect on the LED pixels that are brightest for the longest time, which gives a similar end result to "burn in" on a CRT, with long term static images faintly visible on different content afterwards.
They have not been around long enough for real long-term effects and life to be properly known.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
#13
Re. the life of LED screen TVs; generally on average on TVs from major manufacturers (and random early failures aside) I'd expect ten to twenty years or possibly more.
LED screen are just LCD panels with LED backlights rather than the original cold cathode tubes fluorescent tubes in previous LCD screens. They are well tested technology.
As someone who until recently repaired TV's, the main fault in LCD TV's is 'failure' of the LCD panel - this can be for many reasons, but often to do with the backlights.

Historically they gave predicted lives for LCD or Plasma panels - but this was based solely on light output reduction from the plasma or CCFL phosphurs that generate the light. Both (just as with CRT's) become less efficient as they age, and it's that fact which caused screen burn on Plasma screens, with 'abused' parts of the screen losing efficiency more than the rest.

I'd like to think that LED backlit screens don't suffer from fading, but certainly LED failure is fairly common, particularly on the 'lesser' makes. We were mostly a Sony dealer, and we saw hardly any LED backlight failures, but Sony tend to use higher spec parts than most.

I know a number of people who have tried to repair the LEDs inside the panels, and the general consensus is that it's not worth it, as there's a high risk of damaging the panel, of contamination (you should be in a 'clean' room), and of further LED's failing in the relatively near future.

But the top makes (Sony and Panasonic) are usually reliable and long lived.
 
Thread starter #14
rjenkinsgb - Thanks for the clarification that it's LCD and not DLP. Based on your assessment that the part would be compatible, I am going to take a gamble and buy the part. The optical block also has an internal filter behind each colored panel that I am hoping is the same size as my external "framed" filter. I am planning to disassemble the optical block to get at this internal filter.

A 10-20 year lifespan is not bad for LED. Though you say OLED hasn't been proven in large displays yet, my Sony Vita handheld game system 1st edition uses an OLED screen (it is really crisp and gorgeous) and has been going on strong for a couple of years now. Thanks for answering my question and the technology information. :)

Nigel Goodwin - Thanks as well for your detailed technology description. I think the Firestick is primarily for Netflix and Amazon apps (I don't have Amazon Prime or Netflix subscriptions), but do you know if the Firestick offers its own internet browser? Or is there another Android USB dongle that can offer smart functionality including a web browser for a "dumb" big screen LED TV? I am thinking to buy a "dumb" RCA TV in the future (2160 4K LED TV) for the right price ($289) at Walmart and might want to have internet access on it. Or, maybe I can just use a game system for internet browsing. I know that RCA ain't no Sony, but I think it's a pretty good brand for stereo equipment etc. from past experience. Or would you consider RCA a lesser make? :confused:

Finally, a quick general question: I have an Android ASUS tablet, and I am thinking there must be some TV hardware and software that I can use to stream the tablet contents to the big screen. Do you know offhand if the Firestick allows streaming from a tablet? Or is there another Android USB dongle that would work for this purpose?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
#16
Nigel Goodwin - Thanks as well for your detailed technology description. I think the Firestick is primarily for Netflix and Amazon apps (I don't have Amazon Prime or Netflix subscriptions), but do you know if the Firestick offers its own internet browser? Or is there another Android USB dongle that can offer smart functionality including a web browser for a "dumb" big screen LED TV? I am thinking to buy a "dumb" RCA TV in the future (2160 4K LED TV) for the right price ($289) at Walmart and might want to have internet access on it. Or, maybe I can just use a game system for internet browsing. I know that RCA ain't no Sony, but I think it's a pretty good brand for stereo equipment etc. from past experience. Or would you consider RCA a lesser make? :confused:
As RCA are American only I've no idea what they might be like, but from what I hear through the trade most American brand named TV's are just cheap imports these days (as are most European brand names).

What's on a Firestick depends on what country you're in, I presume the Firestick has a browser? - I can't say I've ever looked - but browsing without a mouse and full keyboard is a pretty dismal process. My Sony Android TV has a browser, but I couldn't say I know where it is :D
 

Dr_Doggy

Well-Known Member
#17
Some tablets have dedicated hdmi output right on them.. .
my tv is not smart but it has DLNA so i just stream media from pc or tab through wifi ... it can not do netflix indpendantly though
 

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