We have a total of 10 projectors in school, one for each classroom. Over time they gather dust and this effects the picture to such an extent that it's only visible in a darkened room. For a while the school thought the only option would be to replace them with new ones, however I came across a post in a news group that suggested that they could be cleaned given a certain amount of technical nous. Upon seeing this I asked David if I could experiment with one of the spare projectors to see if I could revive it - after 9 hours I managed to do it - it was very rewarding!
I posted to the school forum upon completion:
I've managed to revive one of the projectors to its former self and it certainly is quite rewarding. Now it works brilliantly, back up to its 1400 strong ANSI lumens!
This particular projector is quite simple in it's layout and all the main lenses and filters are quite easy to get at. I would have liked to have a bottle of compressed air as this would have probably saved me having to dismantle every part of the projector. The prism assembly is the most complicated bit and having took it apart it took nearly 3 hours to get it back together!
Patience is a must if you go this deep! However it improved my understanding and confidence. Given the right tools, and my newly found knowledge it would take a total of between 3-4 hours to clean. I've spent 9 hours on this particular one, but I'm now familiar with every part of it and have even managed to get hold of a service manual, which came in very handy when I put it back together for the second time and found the colours were muddled up!
Thankfully all the projectors we have, apart from the newer ones are of the same brand - Sanyo, so they are likely to be very similar on the inside.
Oh, and no screws left over!
This is the newsgroup post that inspired me:
Hi there, I have a query, the school technician has been cleaning the projectors we have, but in his haste he has used a compressor and blown air and I think dust into the machines. This has resulted in a grainy and dull picture being projected! Has he knackered them? Can they be opened and cleaned to get them back to their pristine state? Any help/ ideas would be massively useful!
How can these have been cleaned without opening them. The dust inside them is very fine as it has already passed through the filters (similar to static dust on tv screen). So in answer to the question - No its not knackered just that the dust already inside has probably been forced into the lens/filters area.
I clean our Epson and Sanyo projectors by opening them up and stripping them down. I use a hoover to suck out all the dust and an air duster to blow out dust from the lens area.
Take photos at every stage of dismantling so that it can be put back together. You may have to clean the lens and colour filters. These on our projectors just slide out and need a quick wipe with a dry cloth/paper towel.
We are no proactive in that they are now cleaned regularly before the quality deteriorates. You will need to be brave with the first one you do and allow yourself around 4 hours to complete the first time. You will have to undo all electrical connectors and ribbon connectors and remove circuit board to get to all of the dust.
If you do go ahead pick the dirtiest one you can find as you will get a much better idea of the places that the dust can actually get into. It will also be much more rewarding when you put it back together and find that you no longer need to black out the room to see the picture. This is also cheaper than having to pay someone else to pick it up, clean it and then deliver it back.