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Topic: Hitachi Home-1; dirt inside the lens
Joined: Jan 12, 2007
Posts: 25
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Hey projector people.

I've had the Home-1 for a couple years now, and while I'm sure I'll be upgrading to hi-def some time in the future, this thing still has a lot of life left in it. I'm not even half done with the first lamp and I've already got a spare ready.

The problem is, I've already got a lot of dirt built up inside the unit that is impacting the image quality. So far it isn't serious, but if this is how much there is after only 2 years, I'm concerned about what it'll look like in another 4.

I'm sure it's somehow my fault. I take this projector various places to watch movies, including basements and outdoors. While I do pack it carefully, I typically just set it on a table somewhere when viewing. Also, I could probably do a better job of reducing dust in my apartment.

I've attached a photo I took of the dirt inside the unit. I made this all visible by pausing on a black frame of a dvd, putting the projector completely out of focus (to the close end I think) and shrinking the image somewhat. The problem isn't quite as bad as the photo make it look though. Most of that isn't visible to the eye, and a lot of it is just noise from the camera shooting in the dark.

Most of that stuff goes completely invisible when I put the image back in focus. The only exceptions are the bright green strings that create a smudge spot on the image, though only noticeable when the screen is black and during end credits.

So, does anyone know what this stuff is and how to remove it? The unit doesn't look like it's meant to be taken apart by someone who doesn't know exactly what they're doing, but I don't think there's anyone locally who can fix this kind of thing. Also, even if there is it'll likely cost so much I'd rather just live with the problem and save my money for another projector.

Is it possible that a lot of this would go away when changing the lamp, or if in the process of changing the lamp, I could use an air blower somewhere to get at this stuff? I'm not sure about removing the lamp early. I know that these lamps are designed to stop working right at 2000 hours, and I'm concerned removing one would cause it to no longer work.

Thanks for the help!


Dirt inside the projector

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Joined: Oct 2, 2002
Posts: 1,063
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There is always someone you can find to clean your projector/lens professionally either locally or on the internet, either way it has to be shipped or taken into a service store. If it's not impacting your viewing enjoyment don't worry about it and keep your air filter clean.

Changing the bulb will not make this problem go away. Since this projector is well out of warranty you can try cleaning the projector lens yourself by blowing out the dust with compressed air. But if you're not comfortable with taking electronics apart then a service store is your only option. You can find the service manual for disassembling this projector at places like for around $19 and the PDF document is downloaded electronically.

Here is a blog on a somewhat related problem:

But again if you're not comfortable with opening up your projector to clean the inside then forget about it and save your money for a new projector.
[Edited by Crispin on Jan 13, 2007 at 1:27 PM]
My first front projector - a Kloss Novabeam 100 (1986).
Joined: Aug 8, 2005
Posts: 4,417
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It's very easy and common to clean your projector your self. Like mentioned above, simply remove the lamp from the housing and with the straw inserted point the compressed air into the lamp housing. Then with short burts spray in different directions. If this unit has a filter clean it regularly. Sadly it appears that this LCD projector does not have sealed optics. My DLP unit has sealed optics. I have used it like you have your unit, and have used it all over the place for about a year and a half and I have never sprayed it out and there is not a speck of dust in the optics at all. You may consider a unit with sealed optics for your next projector when the time comes, but for now spraying it out should do a fair job.
[Edited by Natja-ss-1334 on Jan 13, 2007 at 3:40 PM]
Experienced with Yamaha Dpx-830sl, Mitsubishi HC1500, Infocus SP7210, Optoma HD80, Optoma H78DC3, Optoma H27,Optoma H31, BenQ 6100,Infocus 4805, and many others.
Joined: Sep 22, 2006
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i use my projetor like crazy in a very dusty environment but never get such dust in mine. if you have a dust filter clean it every hundred hours of use or so, never run the projector without the filter. if you have never cleaned the filter (so many don't do this it seems) you will get the dust buildup that you see there not to mention the increase in heat buildup.
[Edited by jarrod1937 on Jan 13, 2007 at 4:56 PM]
Joined: Jan 12, 2007
Posts: 25
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Thanks for the responses.

I think the problem may have been caused by the filter. While I try to keep it clean, about a year back a couple of the latches on the filter snapped off meaning it doesn't fasten itself very securely inside the filter compartment.

I've seen conflicting information about the appropriate way to clean the filter, including vacuuming the grill on the outside of the unit, removing the exterior filter grill and vacuuming the filter itself, and removing the filter itself and vacuuming it. I've been doing it the last way, and I wonder if it isn't meant to be taken out so frequently.

I went ahead and replaced the filter with the one packaged with my replacement lamp. Perhaps this will prevent the problem from getting worse.

I'll try using an air blower inside the lamp housing and see what that does. If that doesn't work, I'm not sure what I'll do with it.

I contacted Hitachi to find any technical manuals they have and the ones I got don't have any information about taking the unit apart or this specific problem. Because the projector was so cheap to begin with (about $900 including a spare lamp), I'm hesitant to spend much on repairs. However, I have no intention of getting rid of the thing, so I might not have a choice.

Natja, I'll definitely look into sealed optics on my next projector. That's not something I ever thought to look into before.

Thanks again!