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Discussion Starter · #1 ·
My LT150 has been used for 42hrs. I found three 3 inch spots on the right upper corner of the screen. I was sure those were from LT150 but not the screen. It was easy to see the spots when there was no input signal and just showing the NEC logo.


At the beginning, I believed those were the finger prints on the surface of the lense. However, after cleaning the surface of the lense, there were still three spots but shifting to the left upper corner.(The projector has been moved and turned up-side-down.) When I rotated the focus ring, the spots were still at the same position. So I believed the spots were not on the surface of the lense but somewhere internal. Can I remove the lamp to clean the internal surface of the glass facing the lamp?


Some times ago, I found the semi-circular plastic arc below the lense was loose and raised up that caused the lense cover not to be pluged in. I pressed the arc down and then pluged the lense cover in. After that, every thing seemed to be normal. I don't know if the dust got in from gap when the arc was loose. Anyone found the similar situation?



Regards,


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CKL
 

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This must be common on the LT150. I have one small very faint blob on mine as well. It really doesn't bother me and I am afraid if I swap it out, I'll get one that's worse. I also had a friend who had one with two noticeable blobs. He used the Instacare warranty and had it swapped out for one that was perfect. Is this dust? Can we clean it? I'd rather fix it myself.
 

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My LT150 has a similar problem. To me it looks like some type of internal reflection. It appears in the lower right hand quadrant of the screen when floor mounted, or upper left hand quadrant when ceiling mounted. It is only really noticeable when there is no ambient light in the room and the projector is displaying a black or very dark image.


Is this a common problem I should get used to, or should I try and have NEC swap the unit out?


BTW, when swapping projectors under warranty, I assume you get a refurbished unit back, but how much time is on the bulb?
 

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Discussion Starter · #4 ·
I've removed the lamp and found the internal to be clean. So I don't touch it and reinstall the lamp. I also checked the lense closely with torch. I didn't find any spot from what I could see from the surface and underneath the surface. I hope it won't be the problem of DMD chip. I didn't find these spots when it arrived. I think the spots should be dust or mould in between the lense and DMD panel.


I've called NEC and wait for the reply from their technician.


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CKL
 

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CKL, I'm sure that you will anyway, but please post their response to your problem. I sure others will be very interested to know what happens. Also if they offer to send you a new projector, check to see if it is "new" or a refurbished projector and if it will have a "new" bulb.


Good luck!


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Todd

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-scan-lines-annoy-me-

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Discussion Starter · #6 ·
NEC(HK) technician told me that those spots should be dust. He said it was possible the dust was extracted by the fan passing the air inlet and filter to the rear surface of the lense. He requested me to send the projector for them to clean. He also advised to keep the filter to be clean.


I also agree the spots should be dust which shifted from the right hand side to the left hand side after I moved and turned upside down.


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CKL
 

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I have 2 darkish blobs that can be seen on light backgrounds and two very faint "rings" that can only been seen when the image is full black.


I am pretty sure the blobs are dust and the rings are some internal reflection.


When I get around to it, I will send the unit to NEC for a cleaning.
 

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NEC tech said to keep filter clean. What filter? Where is it? Is it in the bulb housing? My VPL-CX1 has a filter panel that can be removed so the foam filter can be cleaned. I could not find such panel on LT150. All I see is the bulb housing.


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Huey ;-]
 

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I have had the same problem with both my Martantz and one of my LT150s. I posted a possible solution entitled "A solution that Sucks!" awhile back. Anyway, I took a vacuum cleaner to the vents on both projectors and it worked! Someone else said they tried the same thing with a different projector and caused some damage, so be careful or you might end up retrieving your colour wheel from the vacuum cleaner's bag. http://www.avsforum.com/ubb/wink.gif


Cheers,


Grant
 

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I took a piece of filtering material, placed it over the pj's air intake vent, and wraped elastic bands around the pj to hold the filter in place. I also have an exhaust fan located behind the pj. This removes the warm air and helps keep the pj somewhat cooler. I can't attest with certainty to the secondary fans ability with helping to eliminate some of the dust particles around the pj, but so far, after 2 months of use, NO PROBLEMS!!!!

I find that, once I'm engrossed with what I'm watching, I don't notice fan noise from the pj or the external fan, especially with the Bose surround sound system and the powered bass I have.

VB
 

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My NEC VT540 manual specifies turning off the projector every 100 hours and vacuuming the outside of both air filters with a vacuum. I do that although I keep my unit in a hushbox with a HEPA filter on the input.


The air filters are actually layers of filter material adhered to the inside of the molded plastic grilles. When you buy a new projector bulb from NEC, two new air filters come in the package.


Gary
 

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I would not reccomend additional filter media be added as it will impede air movement. When you restrict the air movement even slightly the exhaust air temperature goes up. The LT150 already has exhaust temps that are uncomfortably hot, I would specificly advise against anything that compromises cooling, even slightly.


In my VT540 dustbox/hushbox design, I used internal partitions to divide the space into cold (intake) and warm (exhaust) air chambers. Then I added two 12v, 26dba muffin fans that draw air into the cold air chamber through a HEPA filter (a common Eureka vacuum cleaner part). This actually enhances cooling - after two hours of operation, exhaust temps are still about 7 degrees cooler than with the projector in free air. There are 8 alkaline "D" cells that run these fans in the event of a power failure - avoiding projector meltdown inside the box, due to the lack of the 30-second cooldown cycle.


You can get an inexpensive probe and dial thermometer at an appliance store for less than $5, and use it to assess your hushbox performance - a successfull design will cause exhaust temperatures to decline rather than increase.


Gary
 

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I had the same problem as CKL.


The problem occured withen the first 30 days so I was entitled to a brand new machine. But I thought that was overkill so I just sent the LT 150 to NEC and it was returned, clean, 36 hours later. Fedex is amazing (BTW they paid for all shipping)


Call tech support. They have been excellent.


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David

Intel Pentium III 1GHz Processor 133MHz FSB

ASUS CUSL2-C ATX Motherboard with Intel i815E Chipset

Toshiba combo DVD CD-RW

ATI Radeon AGP 64 MB DDR VIVO

M-Audio Delta DiO 24/96 256MB PC133 SDRAM

60GB ATA/100 7200RPM (75GXP) IBM Deskstar Hard Drive

Windows ME

(made by Digital Connection)

And last but not least the infamous Dell LT 150
 

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Is it safe to attach filters directly on the projector's casing over the intake vents like 3.1415926 pi mentioned in his post?


I was wondering if I could do this with the LT150 (intakes on both sides) at least until I'm finally able to construct a dust/hushbox.


Tnx - Sonny B.
 
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