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Posted

We have a Sanyo PDG-DSU21b projector, and over time, white spots have started to appear on the projected image. I would guess it is dust? But where?

 

I have changed the bulb and cleaned the external glass of the lens. But the white spots remain. Could it be something else?

Posted
I have changed the bulb and cleaned the external glass of the lens. But the white spots remain. Could it be something else?

 

Sadfully, the general answer is a pixel is dead. Bearing in mind the lamp only shines light "through" the LCD screen normally, it will just go through as white light.

 

Steve

Posted
Oh dear. I'll have to find out how old the projector is, it doesnt look that old but I guess it could be. Would it be covered by the warranty if it is still in it?
Posted

Generally I think it depends on company/warranty etc, Some say up to 5~ pixels is "norm", some don't etc

 

Might be worth checking a few other ideas first, but pretty much sounds like dead pixel. Is it a lot that are dead? or just 1-2?

 

Steve

Posted

Oh so it is similar to actual LCD screens then?

It is a lot, there is a scattering of them over one side of the board - think it has got progressively worse

Posted
Oh so it is similar to actual LCD screens then?

It is a lot, there is a scattering of them over one side of the board - think it has got progressively worse

 

Well simple version, the lights split (3 colours etc), passed through the LCD screen, which obviously stops certain colours etc etc.

 

If it's dead pixel, aka always "off" its never blocked, so white light.

 

Guess it might be worth checking with the warranty/supplier.

 

Steve

Posted

I meant similar to LCD screens in that a certain amount of dead pixels is considered acceptable - I've never seen them on a projector before so didnt realise

 

Attached an image that shows it fairly well, also some of them flicker a bit

 

IMG_20110407_115921.jpg

Posted

In therory your right but in practice you would have to have a pixel in each screen in the same place to get a white light, so if your right i would go buy a lottery ticket as it would be a one in a milliion chance, but seriously i am interested to see what it is, i have repaired hundreds of these and NEVER seen a white pixel LCD problem i think it more likley to be a contoller issue, but get me a photo and or if you lke i will ring you to get to the bottom of it PM me and i can ring you.

 

Marc

Projector Engineer

  • 4 months later...
Posted

A tad bit late to this thread but was wondering if a solution to the issue of white pixels appearing in clusters was found. I have an Optoma DLP projector and have recently encountered the same problem, the white dots also appear to be increasing in quantity so a response would be much appreciated.

 

Thanks!

Posted

Yes they do get worse we call it creaping coruption, as it seems to grow once started (oh dear another DLP), if its not uner warranty then it will be a replacement, sorry.

 

Marc

Projector Engineer

  • 5 months later...
Posted
I have seen this problem in a lot of infocus and sharp projectors. It is a defective DLP chip, however I have never sent one in for repair so I don't know how expensive it would be. Also I've never been able to order a replacement DLP chip from any vendor either.
Posted
we have had these issues they cant be repaired and tbh i have to change brand im staying away from sony you want to get one these NEC M230X Projector brill i got them from av parts master avpartsmaster.co.uk guy their called paul jennings nice bloke
Posted
We have an NEC NP115. It started doing the dead pixel thing about 2 months ago (the projector is about 2.5 yrs old). It started off with a single dot, and not has hundreds. There are both white ones and black ones, and now there are so many it is nearly impossible to watch. I'll be checking now to see if anything might be covered.
  • 4 weeks later...
Posted

Just to say we've got 2 NEC NP215s now spraying white paint...well that's what it looks like...they are DLP.

None of our LCDs ahd this problem...our older LCDs started to go with a yellow haze.

 

Jon

  • 10 months later...
Posted

Resurrecting an old thread, but this has recently happened to one of our Toshibas. The general consensus is that you need to replace the DMD chip: DMD Chip

 

Considering the cost is a third that of a new projector, I don't think we'll bother taking the chance.

Posted
I've had an Epson do this... and an NEC - both LCD, turned out to be a driver chip breaking down (supplied by NEC) was more expensive to have repaired than to get a new projector.
  • 1 year later...
Posted
Sorry to bring up an old thread but we have some NP200 projectors which have the white dots on. Just got a quote from NEC about this, £500 to replace.
Posted

White dots are usually indicative of dust/ dirt on the lens or the DMD chip is faulty. Might be time to look for some new LED projectors... Depending on what you can afford.

 

How old are the projectors? Still under warranty?

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