I don't understand why I have a 2X2 greenish blur projected on my screen. The green is sort of blending in and around the blur. The LCD Projector is a Sony VPL-CS4. Could I repair this on my own, if so what should I do? or is this going to be a costly repair? HELP!!!

Josh, August 2005

This is almost certainly a spec of dust on one of the lcd panels, it looks blured on the screen when everything else is in focus, if you hold a page at the spot on your projection screen and bring it closer to the lens you can bring the dust into focus, they usually appear like strands of fibre. I have a sony vpl-cs3 and have the same problem with a few spots like this, I havn't tried to fix it yet because I cant work out how to open the projector and i'm not that bothered. If you do open the projector commpressed air should fix it. Never try and fix it by blowing the air in through the fans or other vents as this can move normal dust that would otherwise be of no harm onto the bulb or lens making the problem worse.

Steve, September 2006

Or it could simply be a spec of dust on the bulb. You can take the bulb out and spray with a tin of compressed air, this may solve your problem very cheaply.

Kevin Sinclair, December 2005

It sounds to me like the LCD panel has been damaged, most likely through overheating (ie the heat from the lamp has discoloured the panel) caused by a./ Not powering down the projector correctly (not letting the fan do its job before unplugging) b./ A blocked filter
If the image itself is in-focus, and outside the green blur all colours are fine, then this is the fault. It is a costly repair unfortunately, as to change an LCD panel can cost upwards of 800 GBP, depending on your model.

Phil West, Service Manager, Smartcomm Ltd, November 2005