Barco DP-2k Image Problem

[Kevin Roudebush]

Not an expert but know enough to get myself in trouble. My tech loves me...
We just had an old Christie ballast go out. (Could use one of those if you have one lying around.) Needed a solution to get back on screen quickly.
I got our Barco back up and running. We shut down for 20 months and put all the projection equipment in a storage room (gave up my lease at the time and got back in with SVOG.)
Running on a DSS200. Same set up as before but tech updated software in the DSS200. Technician said Dolby said the DSS wouldn't work without a GORE board. However,somehow when I hooked it up to try it, it worked.
Our problem is the image is "cloudy." It is like there is a fog on the lens. It WASN'T that way the day we shut down.
I know it could be the light engine, reflectors, and color wheels. I'm not looking for those options. I'm wondering if it could be something else that is easy to fix.
We have cleaned the lens on outside. The projection window is clean (smart enough to do those things.)
We did try a DVD to make sure it wasn't a server or cable problem. Same image problem.
Could it be lens on inside?
Could it be the 3D filter accidentally moved over while moving the thing in an out (Our 3D stopped working awhile before we closed.)
Anything else from moving or storing that could have caused this and not obvious?
Thanks for any suggestions. I know it is a long shot and we should get a new projector but just trying to get by to make sure we can survive (we got one new projector when we opened but couldn't get all 3 with my landlords demands so I could get back in the building...)

[Leo Enticknap]

I'm sure that this is the bleedin' obvious and that you've tried this, but...

The only time I've encountered this problem recently, it was the port glass. It was in a Bel-Air Circuit home theater, the owner of which smoked like he was Humphrey Bogart in a '40s Noir. I retired his ancient Series 1 Christie and installed a SP2K-7 in its place. After doing so, I was perplexed at having to max out the lamp power to get 14.3 ft-l on a screen that was only 12ft wide, and at the "cloudy" image you describe.

After much head scratching, the problem was diagnosed as being the port glass on the auditorium side. The layer of nicotine goo on it was so thick that it was effectively acting as a brown filter! I removed the glass and went to work on it with IPA, sacrificing three microfiber cloths in the process. When it was replaced, I got 68 ft-l on the same light setting!

Maybe worth removing your port glass and seeing if the cloudiness goes away?

[Kevin Roudebush]

No problem pointing out the obvious but, yes, the glass is clean and problem with or without the glass. My guess is that if we find an answer that isn't the "reflectors" or "light engine", it might be something most any of you amazing, experienced people here have never seen. Don't know how many times we shut down theatres for 2 years, put the equipment in a unheated storage room and then try to set it all back up. That's why I'm wondering if maybe something like condensation got on the reflectors or something like that. Appreciate your time.

[Leo Enticknap]

All I can suggest is to trace the light path from its origin to the lens, checking components along the way:

• Lamphouse assembly correctly positioned in its slot and the three bolts tight?
• Condition and position of reflector (try adjusting X, Y, and Z)
• Condition of lamp (is the envelope blackened?)
• Condition and alignment of the cold mirror (have the mounting screws worked loose?)
• 3-D unit (if it's NFG, you might like to consider removing it from the back of the light pipe altogether)
• Light pipe / integrator rod
• Fold mirror
• Any visible signs of damage to the prism that you can see, looking between the formatters?

If all of those check out, that just leaves an internal failure within the lens, I guess. Do you have another one that you can swap with, to test?

[Marco Giustini]

Barco projectors are notorious for getting lots of dust at the back of the lens - and on the prism end. That would make the picture very foggy! If you see foggy, the issue is on or after the light engine.
Did you power up the projector when just out of unheated storage? That might cause condensation indeed.

Try looking into the lens with a black pattern shown (be careful of course), do you see anything inside the lens?

I would just remove the lens and inspect with a flashlight (make sure you switch off the projector with the dowser open so you can inspect the prism too).

[Dave Macaulay]

A cloudy image ... I don't know of any way that's from anything except the optical path after the light engine, I don't think anything in the image processing system can make an image "cloudy".

Power down and remove the lens. You slide the metal lever below it across and the lens will pull straight out. Is the lens itself cloudy inside? That's bad - you can't clean it yourself. Is the rear element covered in shite? Clean it.
Look into the hole the lens goes in. If you just see a roundish metal plate, it can be pushed aside, to the left. Gently! the prism face is just behind it.
That glass surface gets dirty. Clean with lens cleaner first, dampen the cloth rather than spraying in there.
If that works, great. If not, try solvent. Barco says acetone is ok but I've only used isopropyl. Need to use lens cleaner after that. It should be super clean. Popcorn smoke deposits a nasty oily film that gets baked to a brown crust by the light's heat.

Note that the rubber ring has to be positioned around the back of the lens mount plate. It's there to stop dirty air getting at the prism face and the lens rear element.

Replacing the lens: align the plug and socket, slide it straight back in until the connector is fully seated and the lens securely back flat, then slide the lever back. Wiggle the lens before letting go of it, it should be very securely locked in. If the locking bars aren't seated the lens can fall out or be tipped a bit (image position and focus will be wrong and unstable).

[Leo Enticknap]

Barco says acetone is ok...

As long as it stays on an uncoated glass surface. If the surface is coated and/or any drips onto a formatter board, that could be very bad news.

Kevin would need to do a lens home and return after removing and reinstalling the lens, to ensure that the focus and zoom positions stored in the lens position files stay the same.

[Dave Macaulay]

I was surprised that Barco says acetone is ok. I don't carry acetone and haven't tried it. Alcohol has worked so far but I suppose really burnt on popcorn smoke oil could need acetone. Definitely just a damp wipe would be used. As long as the lens zoom ring isn't moved, removing and replacing it with power off won't change anything and home/return isn't needed. Some projectors will fail home/return on certain lenses, the lens motor lump hits the rubber and the shift motor stalls. It usually will still go back to a saved position but not always, and then lens files have to be redone.

[Leo Enticknap]

Interesting. It was drilled into us in the Series 2 101 Barco school that a home and return must be done whenever a lens is removed and reinstalled. That having been said, there have been times I've forgotten, and all the presets came back perfectly focused and framed.

[Steve Guttag]

Here is the thing on home and return and why you should ALWAYS perform it when the lens is removed/returned.

When a system is commissioned, step 1 should be the home/return to essentially calibrate the settings on day-1. This lets the CCB know where the lens was when the lens files were calibrated. This should allow a recalibration if something ever goes askew because the home/return re-establishes the 0,0 position for both shifts, focus and zoom.

Why it is important on a lens removal/return is that one normally is going to man-handle the lens/mount a bit and will likely cause the lens mount to sit differently. This is especially true of the "B" series lens mount that doesn't use the linear-bearn upper guide (essentially all of them that the client didn't pay for the upgrade). By doing a home/return, everything about the lens/mount are again, put into the same state as they were on day-1. You can walk up to a projector, nudge a lens and shift an image. Merely selecting that lens file again, won't move it back. Moving between formats may get it setting the same way. Home/return definitely puts it back the same way.

[Kevin Roudebush]

Thanks all. Its looking like it is the lens. Removed (easy) and everything else inside looks good visually. Hope Leo is right about being ok to not do a home & return.
Shine light through lens and it looks cloudy but on the inside lenses that aren't accessible. Got a call in to see if local place might have a replacement.
Don't think I can take it apart and clean it. Can these be take apart and cleaned? I'm doubting they can without significant knowledge, skill and place that is lint/dust free at min.

[Marcel Birgelen]

Since you're going to replace the lens, you'll need to redo lens files anyway, no two lenses are ever exactly the same.

Taking apart the lens isn't for the faint of heart... don't expect to get it back together... The lens is a pretty expensive ticket item and refurbishment may be an option if the damage is e.g. just moisture locked up within the lens.

[Leo Enticknap]

Got a call in to see if local place might have a replacement.

Maybe ask if they could lend you a lens (offer to pay shipping, plus a small rental fee if you don't buy it) so that you can try it, to confirm for definite that the problem is a bad lens? You don't want a bill in the mid to high four figures for a new lens if that isn't where the fault is.

Hope Leo is right about being ok to not do a home & return.

It's a very simple procedure.

S2_homeandreturn.jpg

[Jim Cassedy]

- - - you should ALWAYS perform it when the lens is removed/returned.

I was taught to always do this on NEC projectors too. I haven't had the need to pull the lens off of one
very often, but was told it's always good practice to to do a "home & return' if the lens had been removed.
Also, I think the NEC lens servos, at least on the ones I worked with at a couple of screening rooms &
theaters, had a little bit of "slop" in them and would drift slightly over time as it went from FLAT to SCOPE,
etc and I noticed the focus would drift very slightly. Most people would barely notice, but it was visible to
me on a focus chart or fine print in the credits. So about every 8 months or so, I'd just run another 'lens
re-calibrate' & maybe touch up the focus memory which would bring everything back into sharp focus.

[Mark Gulbrandsen]

I was taught to always do this on NEC projectors too. I haven't had the need to pull the lens off of one
very often, but was told it's always good practice to to do a "home & return' if the lens had been removed.
Also, I think the NEC lens servos, at least on the ones I worked with at a couple of screening rooms &
theaters, had a little bit of "slop" in them and would drift slightly over time as it went from FLAT to SCOPE,
etc and I noticed the focus would drift very slightly. Most people would barely notice, but it was visible to
me on a focus chart or fine print in the credits. So about every 8 months or so, I'd just run another 'lens
re-calibrate' & maybe touch up the focus memory which would bring everything back into sharp focus.

Jim, The lens controller on the NEC is not really a true servo. It does get feedback but not from a generator on the same shaft per say, but in the form of electrical impulses off the motor commutator. If you examine the control board and things on the lens mount you will only see two wires to each motor and no other means of feedback. So that leaves either brush noise, or time as the feedback factor. There is a lot of stuff on the lens driver board...