Cleaning inside a projector (1 Viewer)

[Caleb_O]

Here's an odd problem I have with my NEC-VT540 LCD front projector.
When viewing a dark scene or a completely black screen I can clearly make out two slightly brighter circular blobs.
I'd say they'd be a big as my fists on a 2.4m diagonal screen.
Most of the time they are invisible, and I think one has been there for several months now, but the second one appeared only recently, almost in the dead center of the screen.
I'm assuming they are caused by dust particles, as they can be focused into smaller dots with the manual focus. Damage to the LCD panels would be visible in the pixel structure.
It is a bit difficult to work out where in the projector the dust specks are, but the fact they don't move when the focus lens moves means they are definitely inside. Staring into a projector is dangerous when it's on so I haven't worked out anything more.
So, what to do? Is this a common complaint among projector owners? Is there something straightforward I can do to flush out the specks or do I need a visit from an NEC technician to dismantle the whole thing?
Any help is appreciated,
Caleb

 

[Joseph Bolus]

This certainly does sound like dust particles on or around the LCD panels ...
Most LCD projectors have dust filters that need to be cleaned on a regular basis in order to prevent this very problem.
I take my filters out and "shake them out" after every 100 hours or so of bulb use; and have, so far at least, been able to avoid this problem with my Philips SV20i projector.
While I know of some people that have taken their projectors apart and utilized compressed air on and around the LCD panels, I, personally, would rather let my dealer handle this situation. (I know of at least one case where the compressed air blast actually compounded the problem.)
Joseph

 

[Neil Joseph]

Is your projector under warranty?
I had this happen to my Sharpvision projector. A lot of the time it can happen when taking off the filter to clean it. If you are not careful, the dust can enter the unit at that time. I decided to clean it myself. On my unit, I removed the bulb (very simple) and I removed the fan so I could access the LCD panels. Got some canned air and blew the sucker out.
orangeman
------------------
Neil's H.T. Site
(plus large selection of H.T.Links and movie images)

 

[Caleb_O]

Joseph and Neil, thanks for your advice.
I might look into cleaning the fliter so it doesn't get worse - but I wouldn't want to move the bulb until it's ready to be replaced.
I suppose I could call my dealer and he could open it up, but I've never got on well with my dealer, and this doesn't strike me as a major problem. (I only see it during the darkest of scenes). As long as I can be assured that it is dust, and leaving it there won't cause permanent damage.
But as for as issue of design, why are the bulb (which needs a great deal of airflow to cool it down) and the LCD panels in the same compartment anyway?
Caleb

 

[Neil Joseph]

On my unit, the bulb and LCD panels are not in the same compartment. I just cleaned the bulb and the LCD panels since I had the whole thing opened anyway. The LCD panels (on mine) can be cleaned by removing the filter assembly, and fan, then dusting out with canned air. As one person mentioned, use the air with caution.
orangeman
------------------
Neil's H.T. Site
(plus large selection of H.T.Links and movie images)