# Lamp Glass cracking????



## engtaz (Jul 9, 2010)

I have had 3 to for Lamps that end up with the Glass cracking over time. Cracking is more like lots of little piece broken but still together. The last 1 blew out and took out the color wheel. HT room is running around 73 degrees so the PJ is not in a hot room. Lamps are from different vendors. I have/had a Mit HD1000U.Thanks
engtaz


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## nholmes1 (Oct 7, 2010)

What is the HVAC flow like in your room? Is the projector located next to the A/C vent? Rapid changes in temp or poor ventilation are the most common reasons I have seen for cracked/shattered projector bulbs.


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## engtaz (Jul 9, 2010)

Not near a vent.


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## Mark Techer (Jan 17, 2008)

engtaz said:


> I have had 3 to for Lamps that end up with the Glass cracking over time.


What kind of time frame? How many hours are you getting?


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## engtaz (Jul 9, 2010)

I don't know when they crack because the lamps still are working. The only thing I do notice is that the picture is a little dimmer but not much.


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## Mark Techer (Jan 17, 2008)

engtaz said:


> I don't know when they crack because the lamps still are working. The only thing I do notice is that the picture is a little dimmer but not much.


Lamps in HT projectors are ultra high pressure mercury. If they were to crack, they lose pressure and don't work. They can look craze cracked or smokey when they have exhausted, but they are generally still sealed unless you are finding glass shards inside the housing.

So how many hours on the clock or timer between lamp changes?


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## tonyvdb (Sep 5, 2007)

Are you letting the projector run through its cool down before turning the power fully off if you turn it off at all?


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## MatrixDweller (Jul 24, 2007)

Did it do this with the OEM bulb? I know that a lot of the knock offs sacrifice quality for cost.

Could also be a cooling issue like others pointed out. Do you clean the filter regularly? Is it getting adequate air flow (ie: the exhaust isn't being recycled into the intake)? Is the fan functioning correctly? Is it ceiling mounted or shelf mounted? 

Is it experiencing any movement or jarring? If it's ceiling mounted below a high traffic floor above maybe it's getting rattled around too much. 

Also be sure to never touch the lamp with your fingers. The oils from your skin can cause damage to it when it heats up.

Another question others have posed was the age of the lamp when this happens. If it's close to the rated lifespan (ie: 2000 hours or so) I would chalk it up to it's age and it's probably a non-issue. If it happens much sooner (ie: < 1000 hours) then there is definitely something wrong.


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## Mark Techer (Jan 17, 2008)

MatrixDweller said:


> Another question others have posed was the age of the lamp when this happens. If it's close to the rated lifespan (ie: 2000 hours or so) I would chalk it up to it's age and it's probably a non-issue. If it happens much sooner (ie: < 1000 hours) then there is definitely something wrong.


I asked this twice already and he didn't answer. You can't expect 4000 hours from a 2000 hour lamp (though some do) especially if your running it on high lamp mode.


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## engtaz (Jul 9, 2010)

Bulbs are at less than 1000hrs. It does go thru regular power up sequences and power downs. Internal fans are working fine. Bulb does not go out, glass lens just cracks.


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