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Blue blotches on projector


steve h

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Morning All

 

Our main school hall projector has started showing blue blotches across the screen. It started off small in the corner but have slowly started to take over. They are not completely blue but semi transparent and kind of ugly looking! Ive had all sort of stuff running though it on different inputs so im presuming its a slowly dieing projector...but just wanted to get confirmation or hopefully a way to fix it!

 

thanks

 

Steve

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Its probably dust / dirt on the LCD, though could also be a heat damaged panel.

 

If its a commodity projector then it will be cheaper to throw it away and get a new one than to get it cleaned / repaired.

 

Assuming its a couple of years old then you'll probably be able to get something considerably brighter for the same amount of money that you originally paid. People are sadly misguided about the lifespan of video projectors, in comercial applications it is normal to replace the bulb at 1000 hours and replace the projector at 2000 hours usage. (even if the projector manufacturer claims the bulb is good for 3000 hours!)

 

For your average install projector this means yearly bulb replacement and replacing the whole machine every 2 years. Its a shame that AV installers don't point this out to schools who often seem to expect such a machine to last more like 10 years than 2 years.

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I'd expect it to be very expensive to have someone look at it - last time I had an estimate on lcd panel cleaning and re-alignment it was over £800 - it doesn't make any sense to get projectors at this level fixed. (£2.5k whilst it might sound like a lot of money to a school is not an expensive video projector - the kind of clean room and precision tools required to clean and align LCD panels properly is a very expensive operation to run, generally they are setup to fix projectors which cost 20 times what your projector costs) Cheap LCD projectors simply are not designed with servicing in mind, they are a nightmare to take apart and often impossible to get the panels re-aligned as they were never designed to be serviced and so the alignment process is just doing it by eye, nudging the panels with a stick until they are as close to lined up as possible (ie not very well aligned - you then get a slight colour offset in the image and the whole thing ends up not being as bright as it should be)

 

What make and model of projector is it? How old is it? How much use does it get? Does it get shutdown properly every time its used or do people just pull the power to it?

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Sorry I missed the thread title!

 

Yeah it will certainly be cheaper to get a replacement than to get it cleaned / repaired.

 

I'd recomend a Sanyo PLC-XU106 which has similar specs to your current projector - it costs just over £1000 and has a similar zoom range (so it will mount in the same place and fill the screen you already have) at 4500 lumens its in the same brightness range as your current machine.

 

Sanyo are a good make which is very popular with the AV rental market, they are affordable and offer good functionality for the price.

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Hi Steve,

Just as a note. We replaced one of our hall projectors with a Sanyo PLC-XT35 about 6 months ago. Cost around £2500 with a standard lens, so comparable in price to your current model. The beauty of this model is that the lenses are relatively easy to hire, we have used it for projecting backdrops on shows with a short throw lens and it lives in the other hall with the standard lens for the rest of the year.

Give me a shout if you'd like to pop over and have a looksee.

Ian

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that would be a new one on me, sounds pretty unlikely but its worth having a poke about with it I suppose.

 

Yeah the Sanyo XT range are pretty decent, if you have that much budget to spend. They are kind of entry level professional machines with interchangeable powered lenses and both H+V lens shift. A serious step up (functionality wise) from your current machine, but at more than double the cost of the XU106 you'd want to be pretty sure that the extra features would get used regularly. (eg if you just need to project wide backgrounds a couple of times per year then it will cost less to hire in a specific projector for those shows than to spend the extra on the XT35)

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had a poke around and nothing changed. Also looking at the screen I can see the blotches are forming patterns of what use to be on the screen. - eg a "start" button is visible in the bottom left so deffos on the hunt for a new one now...thanks for the help!
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had a poke around and nothing changed. Also looking at the screen I can see the blotches are forming patterns of what use to be on the screen. - eg a "start" button is visible in the bottom left so deffos on the hunt for a new one now...thanks for the help!

 

My initial thought was possible contamination from Smoke/Haze fluid where a projector has been used in an environment where these things are used. We had a lot of problems with this a while ago where the haze gets sucked in via the cooling fan and leaves oily deposits on the LCD Panels, the panels can be cleaned but it's not easy!

 

Reading the post above makes me think you have "Burn in". When an LCD CRT or Plasma screen has the same image displayed for inordinate lengths of time the image gets burned in onto the display, some limited success has been achieved by running a full white raster with the brightness/contrast up at max, you can try this but I wouldn't hold your breath, it's probably knackered!

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Reading the post above makes me think you have "Burn in". When an LCD CRT or Plasma screen has the same image displayed for inordinate lengths of time the image gets burned in onto the display, some limited success has been achieved by running a full white raster with the brightness/contrast up at max, you can try this but I wouldn't hold your breath, it's probably knackered!
You could also try http://www.jscreenfix.com. It rapidly and randomly toggles the pixels on and off, which will probably help with the burn in. It's also free!
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