Barco DP20-C Lamp Issue

[Rick Cohen]

I am servicing an indoor screen that is experiencing a light issue on just the left side of the screen. The bulb has been installed for about 1/3 of it's warrantee life. There is a dark area on the far left of the screen. It only appears while in scope format, not in flat. I tried adjusting the X-Y-Z axis on the lamp house, and there was no change. My next step is to pull out the lamp house and inspect the lamp. I would prefer not to adjust the light tunnel unless absolutely necessary.

[Colm Nolan]

My first instinct would be to check if there is anything physical obstructing the light, is there anything on the porthole or the frame causing the dark area. After that to cross swap a lamp house, if you still have a dark spot then you know its the the light tunnel

The dome could also be damaged inside the lamp house from lamp changes

[Steve Guttag]

Most likely the fold mirror is out of alignment (and possibly some light pipe alignment).

[Tj Hopland]

Did you have a look at the image coming out the front of the lens? Maybe there is some extreme lens shift going on and this lens model in this zoom position has internal issues getting the light through? Its usually pretty easy to kinda see the frame of light in the front of the lens and judge if its a reasonable distance from any of the edges. You could also compare that to flat and see what its doing, you may see the inner parts of the lens light up more in scope if its shifted far enough to be hitting something internally.

While you are looking at the front of the projector look and see if the 'boot' between the front cover and lens holder is in place. I see it a lot with the C's where when changing the front filter someone pulls the cover far enough out that it puts enough pressure on that boot to pop off. With that off its kinda a dirt sucking vortex up there between the back of the lens and the front element of the light engine.

It would be a little odd its just scope since on the .98 scale there isn't that much difference between scope and flat so it would seem like some random fuzz would not just pick those last few pixels to obscure but who knows how the air is actually flowing back there especially if that boot has slipped off.

[Dave Macaulay]

By removing the lamphouse and lens with dowser open, you can look in at the prism while shining a flashlight into the light pipe orifice. A cracked lens or light pipe will look pretty weird. It should be a rectangle of relatively even light. A prism or folding mirror problem may be visible as well. I found a cracked lens in the light pipe this way. You may need to load a full white pattern, the DMD chips stay at the last image used.
The front face of the prism can get dirty if the lens seal was not installed correctly. Can be cleaned with acetone if alcohol doesn't work. It's a bugger to get the seal locked on with the lens in place, if possible at all.