HC1500 dust blobs issues...

I purchased a HC-1500 last Sept & have been very happy with it (until now). I recently moved, setup the projector at my new residence & now have 12 + dust blobs. The pattern is very strange - most of them are "around" my 100" screen. I can see them on the wall (except for a few) outside of the screen.

I bought this projector mostly because I hadnt heard of any dust blob issues. Now Im plagued with them.........

I've got the same problem. Probably got aroun 10 of them. 2 or 3 outside of the screen. I bought it off ebay and he says it was purchased in march at best buy so I'm assuming it's still under warranty. He's gonna get a copy of the receipt and I'll probably just call and see if they can fix it. Ugh, that prolly means I have to pay for the cost of shipping unless there is a local place that will clean them.

I feel your pain - I returned 2 Acer PH530's because of dust blob issues... Im starting to tire of setting up & battling projectors

Great, thats news to me about the dust blobs on the HC1500. So far I have none, I will make sure to clean the filter once a month. My old Panasonic L500U is over 4 years old without blobs, might be from running an air filter in the room 24/7.

I don't believe the HC1500 has an air filter, since it uses a sealed optical path.

That is correct - no filter to clean.

Open it up and blast some dry air using a hand, animal-balloon pump (avail. at party favors section at Walmart, red/blue body with yellow tip). Canned air can be flammable if PJ is hot and can spew liquid droplets which can cause even more damage (as the path is "sealed" so you can't use Q-tip to clean the droplets off). It's even better if you have your assitant to hold a strong vacuum nozzle next to the optical block to pick up any loose dust dislodge by your blasting.

FWIW, you can buy non-flammable canned air for a couple of dollars more, but that still doesn't alleviate the potential of liquid droplets. Of course, I've used canned air for years and never had a problem - you just have to make sure you hold the can upright.

You NEVER want to blow any air into a hot projector. The sudden shock, if the air comes out cold, WILL shatter the lamp and may do other damage.

NEVER while the projector is hot, period!

Isn't that a given? If someone were foolish enough to do that, they deserve the consequences. I was just pointing out that there is such a thing as a non-flammable air duster.

How can you get dust blobs if the optical path is sealed?

To sensible people like you and me, (and I'm not sure about me sometimes), yes, it is given. I was responding to heut's post , which reads in part Canned air can be flammable if PJ is hot which is what prompted me to say what I did.

I am wondering about the same thing. Supposedly, all the problems related to dust blobs should have been history with the introduction of the so called "Sealed Optics".

Sealed is a relative term. It doesn't take a huge gap to get tiny dust specs in the optical chamber. Air is constantly moving inside a projector. ANY tiny break or gap is enough to allow dust to enter. I think you hit it when you said "SO-CALLED"

One other point, any dust spots visible in the image will NOT, NOT be on the color wheel. It HAS to be in the imaging chamber and quite probably on the imaging device itself. This point is directed at those who have asked or will ask that question.

Has anyone had any luck getting rid of the "dust blobs"? I've only had mine for 6 months, and I've got them everywhere. I called one local Mitsu "service center" and they said cleaning is not under warranty. I'm waiting on hold with the national tech service, so I'd like to get a feel for how much it'd cost if it isn't under warranty. If this is the way their customer service really is, I won't be buying anything from them again.

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.

I had mine in for cleaning recently. Waste of gas. They just shot some air into it, which made the blobs move, but did nothing to get rid of them. If you want to take it in for warranty, talk to their offices in California. I just took it to some local place.

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.

hi all,
has anyone actually removed dust blobs successfully yet from an hc1500 or 1600? I replaced my bulb and now i have them and it's driving me insane.
thanks.

Visible dust blobs on a DLP are going to be INSIDE the imaging chamber. Which means you will have to open the projector and remove the cover over the chamber to expose the optics and display device. Then use canned air (NO VAPOR) to gently blast away the dust.

There is no way you can get to the dust from outside the projector.

Since you say the dust appeared after the lamp change, did you by chance blow any air in the lamp chamber to clear any dust? If so, you inadvertently blasted some dust into the chamber.

yes, i did... and i feel like a complete stooge. hopefully i can reverse this situation...

Had the same issue with my HD1000U - same model pretty much.

I made a guide and took pics of my experience. After cleaning, it's sharper and brighter - oh, and no more annoying dust blob....drove me nuts when I had it.

http://www.avsforum.com/avs-vb/showt...ight=dust+blob

i followed your guide and it worked! thanks so much.
my wife and kids were worried there for a bit when i had it taken apart, but it wasn't so bad.
thanks again.

I'm so glad it helped. It took me months to get up the nerve to do it myself, so I thought taking pictures and documenting would help others in my situation.

I would do it again if I get a dust blob without hesitation.

Just to follow up on my blobs. I sent the projector back to Mitsubishi and they cleaned the blobs out under warranty. No more blobs. But my projector has started getting a flicker on low power. Bulb at 2000 hours now. Is this a sign of a failing bulb?

It can be, but not necessarily. I have had the flicker problem on a couple occasions in the life of my HD1000. The first time was at around 500 hrs and I got rid of it by cycling the bulb from low to high power a couple times. The second time it happened was on a lamp with probably over 7500 hrs on it and no amount of cycling would get rid of it. Of course, by then this lamp was already so dim that I changed it out prior to it dying completely.