Film-Tech Forum ARCHIVE: Barco DP2K - 23B Reflector replacement

This is topic Barco DP2K - 23B Reflector replacement in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Barry Floyd (Member # 385) on 08-21-2018, 08:39 AM:

Last night when changing out the lamp in one of my projectors, the brass adapter on the new lamp slipped out of the rear socket fitting and landed on the reflector and broke it.

I've been to the Barco Level 1 Installation / General Maintenance class, but we didn't go over reflector replacement in that class.

How hard it that going to be to replace? Is that something I can do, or do I need to find someone to come do it for me?

Posted by Mark Gulbrandsen (Member # 72) on 08-21-2018, 11:18 AM:

Last I had to replace one they preferred to supply an entire lamp module rather than the reflector. Not sure they still push that or not.

Mark

Posted by Dave Macaulay (Member # 813) on 08-21-2018, 11:51 AM:

Don't know your skill level but it isn't too bad. Pretty much disassemble the lamphouse: unless I'm just remembering the C lamphouse (the smaller B lamphouse is very similar I think) the assembly screws to both sides of the mirror bulkhead plate, the new mirror comes on a new plate. Lots of screws. Keep track of what length goes in what hole.

Posted by Barry Floyd (Member # 385) on 08-21-2018, 12:04 PM:

I just had someone send over the replacement instructions from the Barco manual. Doesn't look as complicated as i feared. My equipment dealer is locating the part now and getting it shipped today. I should be able to tackle this now that I have illustrated instructions.

Posted by Monte L Fullmer (Member # 2797) on 08-21-2018, 06:06 PM:

Good luck with the install.

Any focusing procedure needed, or just a straight shot install?

Posted by Dave Macaulay (Member # 813) on 08-21-2018, 09:00 PM:

I believe the new mirror comes on a thick metal plate, the lamphouse registration pins on the projector engage that plate. So alignment of the mirror to the projector should be maintained: needs only normal lamp alignment. The folding mirror should not need any alignment (that is not a fun job).

Posted by Barry Floyd (Member # 385) on 08-21-2018, 09:05 PM:

Monty,
Looking at the installation instructions I was forwarded today, it looks like a straight up install. Any focusing I believe is going to be down with the lamp adjustments.

Honestly, it looks pretty simple.

1. Disconnect the cathode wire from the lamphouse.

2. Cut a zip tie.

3. Remove 4 screws from the bottom of the front section of the lamphouse.

4. Remove 8 screws to separate the front of the lamphouse from the back.

5. Remove 3 hex socket screws that hold the reflector mounting ring to the lamphouse.

Reassemble in reverse order....

Posted by Steve Guttag (Member # 268) on 08-22-2018, 12:34 AM:

Most everything on modern Barco projectors is easy to service. I doubt too that you'd need to adjust the cold mirror (unless you really wanted to optimize it and even then you should have something like the old USL PSA200 light meter to measure uniformity).

If you follow the instructions, it shouldn't be bad at all.

Posted by Marcel Birgelen (Member # 6801) on 08-22-2018, 02:23 AM:

Maybe a redundant tip, but anyway: Use a bunch of CLEAN gloves when handling the mirror.

Posted by Chris Markiewicz (Member # 1415) on 08-22-2018, 09:58 AM:

Done several of these. You may need to tweak the top of the bulb module housing with a screwdriver to tease the reflector flange out of the housing. Same on install. Otherwise it's pretty straightforward. Make sure you have a good sized work surface.

Posted by Barry Floyd (Member # 385) on 08-24-2018, 10:09 AM:

Got this repaired last night, and it went better than expected.
Our dealer (American Cinema Equipment) and Barco made sure the reflector got here on time and in one piece.

Tuesday night I went down to the drive-in and took apart the lamphouse to familiarize myself with the procedure, and made sure I had all the necessary tools to complete the job.

A fellow drive-in owner had sent me a couple of pages from the Barco service manual, but I found out the hard way that there seems to be an "early model" and a "late model" revision to the 23B lamphouse. My instructions didn't match the lamphouse sitting on the bench. I called Barco and they sent me the entire REVISED service manual for the 23B & 32B.

New reflector arrived yesterday afternoon, and I had it all put back together and back up and running by 8:30 p.m. last night. Got the new lamp alignment dialed in to 13.38 foot lamberts... I'm pleased.

Posted by Stephan Shelley (Member # 8587) on 08-24-2018, 08:32 PM:

How big is your screen. That is very impressive for a drive-in.

Stephan

Posted by Mark Gulbrandsen (Member # 72) on 08-26-2018, 09:31 AM:

Digital works very good in drive in situations. My DI customers have as good an image as their indoor screens have.

Mark

Posted by Dave Bird (Member # 490) on 08-26-2018, 06:09 PM:

For what it's worth, our drive-in screen is 73 feet wide and we use a 23B. Our bulb is "turned down" and we still achieve proper brightness, no problem. Can't recall what the meter read when they did it, somewhere around 13 as I recall. The picture was most certainly "too bright" at full power.

Posted by Barry Floyd (Member # 385) on 08-26-2018, 09:32 PM:

quote: Stephan Shelley
How big is your screen. That is very impressive for a drive-in.

Both of our screens are 25'-0" x 59'-0"

Posted by Stephan Shelley (Member # 8587) on 08-29-2018, 04:01 PM:

I did an install at a DI 40' x 100' screen with a Barco 32B 4K running a 65000 watt bulb. 5 ft-L scope and 9 ft-L flat at full power.

Posted by Sascha F. Roll (Member # 9043) on 08-29-2018, 06:45 PM:

65 kw? Is it nuclear powered? [Big Grin]

Posted by Stephan Shelley (Member # 8587) on 08-29-2018, 07:10 PM:

Oops 6.5 kw. One too many zeros.

Posted by Barry Floyd (Member # 385) on 09-07-2018, 03:44 PM:

Since our Screen 2 with the new lamp and reflector looked SOOO much better than Screen 1 - I went ahead and replaced the lamp on that side too (it still had 179 hours left on the lamp).

I replaced the lamp with a brand new Ushio DXL-40BAF/L (4200 watts) and no matter how many times I did the lamp alignment procedure, the best I could squeeze out of it was 9.28 ft/l.

I actually swapped the lamp house modules from Screen 1 to Screen 2 to see if the light output sensor was giving false readings, but got the same results.

Would a new reflector really make that much difference? Everything inside the lamphouse was as clean as it could be.

Posted by Steve Guttag (Member # 268) on 09-08-2018, 10:33 AM:

It is certainly possible. I'm noting, across the board, light fall off on systems that have been in a number of years. I'm most curious if it is a particular piece of the optical chain or a cumulation of dust and such throughout (losing a little on the reflector, the mirror(s), the light pipe, any condensing lenses, notch filter, prism...etc. I've cleaned the stuff easily cleaned.

In some cases (many actually), the screen is the main culprit. This is evidenced by the light meter in the projector not changing its level much (so the light level up to the fold mirror hasn't changed much) but the light from the fold mirror to the screen has degraded. Presuming the prism area is reasonably well sealed up (except for NEC with the gapped double prism) there is maybe a condensing lens, notch filter and the prism itself...and the SCREEN. HVAC system seem to love to pump dirt onto the screen as well as the screen surfaces degrade over time. If you were using a gain screen then they seem to be the most affected.

If you are seeing the light different in the on board meter then your issue is lamphouse through the light pipe and if swapping the lamphouses does the trick, then it really points to the reflectors.

Posted by Chris Markiewicz (Member # 1415) on 09-08-2018, 09:59 PM:

Looks like the possible causes for low light readings have been covered. I lean toward the screen being the most likely problem. How long since it was last power-washed and repainted? Another thing to check; is the end of the light pipe visible with the lamp module removed marked or discolored at all?

Posted by Barry Floyd (Member # 385) on 09-08-2018, 10:18 PM:

These light output readings were taken from the Barco Communicator software, so I really doubt the Screen surface condition would make any difference, since the screen itself doesn't come into play with the software.

Posted by Dave Macaulay (Member # 813) on 09-09-2018, 07:34 AM:

Yes, but the light sensor numbers are supposed to be calibrated to the screen Ft-L reading during maintenance. Even then they are not very stable, I rarely find them accurate on the next calibration... reasonably close but far from exact. There's no way I know of to get the raw sensor reading to make any long term comparisons as components age (and the sensor itself may be aging and change sensitivity).