Originally Posted by flintlock
I have about 5 dust blobs on mine. One on the upper left of the screen, the rest are off the screen! If Mitsubishi won't cover it under warranty, it will be the last Mitsubishi product I ever buy. Very disappointed.
Dust is an inevitable part of owning a projector unfortunately, and IMO the biggest PITA with them. Dust blobs are extremely annoying, and really ruin the enjoyment of watching a movie. Any time a dark scene occurs you immediately start looking for the blobs (at least I do, but maybe I'm OCD
No matter what brand you buy, even the best sealed PJ can and will get dust in the optical chamber over time. My advice is learn how to take your projector apart and get rid of the dust yourself. I've done it with two different projectors, and it really wasn't hard at all. They were both Infocus PJs, and the approach was the same - take the lens assembly out, which reveals the DMD (DLP chip), and use compressed air to clear out the dust. It's usually not that hard to get the lens assembly out, but you do need to do some disassembly. If you search you'll find some how-to info, although I don't know if there's any for the HC1500. Here's my instructions for doing it on the Infocus IN76:http://www.avsforum.com/avs-vb/showt...6#post15764906
The HC1500 is obviously different than the IN76, but the approach should be similar.
I've found that the most important thing after you've had your PJ for a while, is to make sure you never move it unless you absolutely have to. Both times I've gotten blobs was after my projector was moved. The 1st projector (4805) got several blobs when I was adjusting its mount position and it got inadvertantly jerked to the side. The 2nd projector (the IN76) was when it was shipped back to me after a repair.
Speaking of which, if you ever need to ship a projector, ship it with the lens facing the bottom of the box. That way any dust shaken loose will fall on the lens (and not be visible in the projected image). If lens is facing up, that means the dust has a greater chance of falling on the DMD (usually opposite the lens), which WILL be visible in the projected image (or on your wall).
That's also part of the problem with sending it in for a cleaning. It could be dust blob free when it leaves the repair facility, but be re-blobbed by the time you receive it, after UPS is done shaking the hell out of it.