Query Sony Grand Wega 42sx300 LCD rear projection TV

[Guest]

Hi all,
i have been given one of these free of charge. It basically works fine but when viewing certain colours/backgrounds on the screen,there are sometimes what appear to be small pink or purple blobs scattered randomly across the screen. Its often barely noticeable. My research leads me to think that this may be caused by dust particles on the light block/mirror assembly?? I am not 100% sure of the technology used here but it has been suggested that i could blow the dust off using compressed air in an aerosol?? the only thing is, i dont know where to find the light block/mittor assy ??

I removed the lower back panel to have a quick look at it is quite dusty in there. The previous pwner sanded his floor without covering the tv !!

any clues welcome

[gary]

THE OPTICAL BLOCK UNIT IS THE LARGE ASSEMBLY VISIBLE IN THE MIDDLE OF THE SET BEHIND THE STEEL BRACKET THAT IS EXPOSED WHEN THE BACK IS REMOVED, SONY SAY THAT UNDER NO CIRCUMSTANCES SHOULD IT BE DISMANTLED OR ANY ATTEMPT AT SERVICING IT BE MADE, THEY HAVE A FIXED PRICE FOR SERVICING IT WHICH IS IN THE REGION OF £500 FOR DEALERS!!!. YOU COULD TRY COMPRESSED AIR FROM AN AEROSOL CAN AND IT MAY IMPROVE IT BUT IF YOU TAKE THE UNIT APART IT BECOMES UNREPAIRABLE AS ALIGNMENT REQUIRES HIGHLY SPECIALISED JIGS AND A NEW ONE IS MORE EXPENSIVE THAN A NEW SET. WORTH ATRY THOUGH AS YOU HAVE NOTHING TO LOSE.