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sony..spots?????

m29g
02-26-2005, 11:37 PM
hello folks..i was wondering if any of you who own a sony lcd tv..i'm from canada and the model is kf50we620. my tv once turned off displays green little spots,in same location before the screen goes completly black. i heard that this maybe cause by dust on the mirror,once the set is turned on again,and the picture resums,the dots are not noticable unless it's a extremly dark screen ......any imput would be great....thanks in advance

m29g
02-27-2005, 08:38 AM
does anybody know what i'm referring too whan i say "spots"

Beastslayer1
02-27-2005, 08:56 AM
What you are probably noticing are "Dead Pixels." This is when the Diodes that either allow or blocks (depending on what signal is sent from the processing brain (on or off)) the backlighting from passing through are disconnected from the processing brain. This problem is an acceptable condition for LCD technology and Plasma technology, to a certain number of pixels and yes, location of the dead pixels does matter. I would highly recommend that you have a service tech called or take the television to a tech. This condition is irrepairable...most of the time. However, still take it in to have it looked at...

crazyal
02-27-2005, 09:45 AM
How small are these spots? There are no mirrors like a DLP would have and I think Sony uses a prysm system not a mirror to direct the light but I'm not positive about that. Each lcd pixel is about 1/32" in size on the screen so if the spots you are seeing are than small then my guess is your green lcd panel has lcds stuck open. I've heard there is a way to exercize them to see if they will close. Again I just remember an article talking about it but forget the details.

LCD's are like a door, either open or closed. There are three panels, each one has either a red, green, or blue mask. The light from the bulb passes through the mask to change it to one of the primary colors and the liquid crystal either opens to allow the light through or stays closed to block it depending on what signal is sent. If a crystal stays open then light from the bulb will always pass through. My Sony takes a few moments before the bulb powers down after turning it off yet all the crystals are closed so only black should be displayed (a good time to look for bad crystals).

m29g
02-27-2005, 12:01 PM
these spots are little smaller than a ping pong ball,i spoke with a sales rep at a local sony store he said that this style of tv actually had one BIG mirror, on which the projected image is shot at ,then back to the screen....i did speak with an authorized service center and they said that the problem is not dead pixels,has anyone experienced something similar?

Beastslayer1
02-27-2005, 03:22 PM
Yes...a customer of mine experienced the same kind of problem on the 60VS810 LCD RPTV. That television was so new we just swapped it out for a new one, and sent the problematic one to service. It was repaired and sold. So as long as it is the same problem, it should be repairable.

m29g
02-28-2005, 06:15 AM
beastslayer1...i was wondering if your service dept,or technicians actually found out what the problem was specifically?

Rubicon
02-28-2005, 08:12 PM
My Sony 55" is doing the same thing. It's gets a little annoying during dark scenes. Anyhow I have no idea what causes this.

jgraham34
02-28-2005, 08:53 PM
I am having the same problem I have 3 pixels out now. Last night I had none and now 3. In the middle of the screen. And 2 of them are together.

m29g
03-01-2005, 01:55 PM
do you guys know if they are dead pixels for sure,i did a little research,and spoke with company reps,they assured me that the problem is NOT dead pixels,they went on to say that if they were dead pixels,then that portion of the screen would not display ANY picture whatsoever,this isn't the case with my tv.....the 'SPOTS' are only seen on black picture screens,and not seen at all when the set is turned off.........but when a nice high definition picture requires colour...these areas still display as needed...

Beastslayer1
03-01-2005, 05:16 PM
I apologize for not posting, I've been very busy witha recent career change. If they are indeed ping pong size, then they are not dead pixels. However, it's probably a piece of dust or dirt that has fallen and is blocking the light path from one of the LCD panels. Remember, LCD RPTV use three LCD panels, one for the reds on an image, another for the greens on an image, and the other for the blue on an image. All three shades or projected into that "prism"(threre the three are combined into single entity) and then shot onto a mirror then onto the screen. Now in order to make a solid black picture it takes an equal intensity of all three primary colors (red, blue and green.) If one of those panels are being blocked (by a piece of dirt or dust), then depending on which one is blocked that area would appear a certain color. The reason the spots only appear at certain colors, is because as the picture refreshs and LCD panles subpixels change color, they are changing to the color that has one of its primary colors being blocked.

m29g
03-01-2005, 07:28 PM
thank you beastslayer....you agree what the tech's at sony are telling me.....do you think a can of compressed air may be able to get it (dust particle) of the "mirror" ? and get the black images back to normal??

rudyusmc1980
03-01-2005, 08:07 PM
I had a similar problem with a philips lcos last year. I never did figure out what was causing it. The light engine was replaced once. This fixed the tv, but the problem was back about a month later. The tech refused to fix it again without talking to philips. It took another 2 months of haggling to get the tv exchanged. Out of 8 months or so, the tv was broke 6!

My spots were softball sized, about a dozen of them, and spread out all over the screen. They were easily seen from 10 feet away in any dark scene.

good luck on your set

Beastslayer1
03-01-2005, 11:36 PM
A can of compressed air could do the trick, but you would have to disassemble the television on order to get to the projector assembly in order for it to be effective (if that is what is causing the problem.) Just shooting it into the back of the tv just will not do. The three lcd panels are in the heart of the projector. Do not attempt this unless you are or know a technician who is factory certified to do so...

m29g
03-02-2005, 09:18 AM
does anyone think that warranty would cover such a thing???

jgraham34
03-02-2005, 10:10 AM
does anyone think that warranty would cover such a thing???


I am curious to know as well. I have more and more green spots showing up when the screen goes black.

Beastslayer1
03-02-2005, 11:12 AM
I believe it should, especially if you bought the stores extended maintenance warranty. But, it depends on what is wrong with the television, and if that problem is covered within the warranty. That's something to take up with Sony or the stores Service Plan Department.

m29g
03-02-2005, 02:10 PM
yes i'll check into it and see what answers i can come up with...........meanwhile,we should start a coalition.....ha ha

m29g
03-03-2005, 09:45 AM
I had a similar problem with a philips lcos last year. I never did figure out what was causing it. The light engine was replaced once. This fixed the tv, but the problem was back about a month later. The tech refused to fix it again without talking to philips. It took another 2 months of haggling to get the tv exchanged. Out of 8 months or so, the tv was broke 6!

My spots were softball sized, about a dozen of them, and spread out all over the screen. They were easily seen from 10 feet away in any dark scene.

good luck on your set



what exactely were the tech. telling you in reference to your set problem????

doug30
01-04-2006, 07:47 AM
This maybe a dead issue but I experienced the same thing with my 42" GW620. There was dust on the lense. They just replaced the optical block and it works and looks fine for now. I'm keeping my fingers crossed.

4evervettes
01-04-2006, 06:50 PM
Hi the condition with the green gulf ball sized blotch or blotches is exactly what you said about the dust that is on the polarizing lens inside the optic engine. This is NOT a burn't pixal or ahything serious,it involves taking the back off the set and the optic engine then the service guy will spray compressed air to clean the lens and then problem fixed no more spotes in dark seens or when the tv is shut off and the screen is still lit. hope this helps you 4evervettes

doug30
01-05-2006, 11:24 AM
They blew compressed air into mine. After he put it back together..i had this big red blotch in the middle of the screen plus a couple of yellow and blue spots. I was pissed. He then ordered a new optical block(which was on back order for a month). It works and looks fine now thank goodness. I was told on another forum there is no sense in blowing compressed air into the unit because it will come back eventually. I agree with that assessement. Just order a new optical block and hopefully be done with the problem.

flycj
07-06-2009, 05:00 AM
I apologize for not posting, I've been very busy witha recent career change. If they are indeed ping pong size, then they are not dead pixels. However, it's probably a piece of dust or dirt that has fallen and is blocking the light path from one of the LCD panels. Remember, LCD RPTV use three LCD panels, one for the reds on an image, another for the greens on an image, and the other for the blue on an image. All three shades or projected into that "prism"(threre the three are combined into single entity) and then shot onto a mirror then onto the screen. Now in order to make a solid black picture it takes an equal intensity of all three primary colors (red, blue and green.) If one of those panels are being blocked (by a piece of dirt or dust), then depending on which one is blocked that area would appear a certain color. The reason the spots only appear at certain colors, is because as the picture refreshs and LCD panles subpixels change color, they are changing to the color that has one of its primary colors being blocked.

Thanks for the info - I have a tech scheduled to diagnose this very same problem but was wondering what are the pitfalls of carefully clearing the dust using compressed air - can the air affect prism alignments and such?

Tuvok777
07-06-2009, 01:11 PM
Howdy,It could also be a problem with the lcd chips.This is a common failure on the Sonys.Its composed of 3 chips that are blue,green and red.Thses chips are melting do to the heat.If you are getting either of these colors with dot shapes or on the corners as a blur that;s what it is.Unfortunately they don't sell the 3 lcd chips by themselves you will need to replace the whole light engine.Good luck,and God bless your house.;)

R2D2repair
07-09-2009, 10:57 AM
Hi,It sounds like the 3 Lcd chips are melting ,this is a common failure on Sony tvs,(It's also happenning to mine).You will need to replace the light engine.