quote: Dave Macaulay

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If it's still got blue dots, you can either live with them (and they are likely to get worse over time) or have the prism replaced or repaired.

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I guess you mean the DMD . Although, a new light engine usually is a better option than having yours refurbished. Refurbishment can take forever and in the end you might not get your own light engine back, but an entirely other one.

What I've seen is that some DMDs seem to have some kind of "pixel rot", once one starts to fail, others are prone to fail too. Maybe that's because one failed because of a bit of debris got stuck in there. If that one gets dislodged, it can start to affect other pixels.
 

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Posted by Mark Gulbrandsen (Member # 72) on 03-09-2019, 07:50 AM:
 
Actually in the case of NC-2000 it is way, way less expensive to repair it via Strong than it is to buy a new one. A new NC-2000 light engine is ~25K USD, while repairing it is in the USD 4 to 6k dollar range if it's only one DMD and cleaning that needed. I was lucky in that I was able to secure a brand new light engine a couple years back from MIT that was out of a shipping damaged projector for 15K. The engine it was replacing had bad pixels on all theree DMD's from demolition done right next to the machine.

Mark
 

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Posted by Steve Guttag (Member # 268) on 03-09-2019, 08:38 AM:
 
These companies really need a good RX program for light engines. It is BS that they don't have them on the shelf ready for the next failure and then merely repair the one that comes back. What is going to go wrong with them? The DMD or a formatter. Figure out what that costs and the clean/realignment and come up with a fair repair price for the RX. We used to do it for intermittents in the film days.
 

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Posted by Mark Gulbrandsen (Member # 72) on 03-09-2019, 12:16 PM:
 

quote: Steve Guttag

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It is BS that they don't have them on the shelf ready for the next failure and then merely repair the one that comes back.

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quote: Stephan Shelley

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I have not been able to find the alternating checkerboard on the NECs

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> There is a flashing-checkerboard on You-Tube that I used once in a pinch.
(and it worked! )

It only runs about a minute, so I just downloaded it & had it repeat overnight.

Flashing Checkerboard
 

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Posted by Carsten Kurz (Member # 5396) on 03-10-2019, 08:38 PM:
 

quote:

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and it worked! [thumbsup]

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quote: Carsten Kurz

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Can you tell us more?

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This was a small, neighborhood theater that sometimes calls me when
they have a problem. They reported a "blue spot" in the upper left quadrant
of the screen. At the time, I was getting ready to leave town for another job,
so I didn't have a lot of time to deal with it. I went down to the theater & I
did see what appeared to be a 'stuck' blue pixel on the screen. It wasn't
'horrible', but it was definitely there & once you saw it, it was hard to ignore.

As the theater was short on money, and I was short on time & didn't want to
spend all night at the theater, ( I had a 3am airport shuttle pick-up the following
day) I decided to do the checkerboard thing as sort of a 'Hail Mary' fix for them.
Not finding an alternating checkerboard pattern on their projectorthingy (an NEC)
I created one for them & told the to let it run until they opened the next day.
(so it ran about 14 hrs)
I got a text message the next day that the 'blue pixel' was gone. This was about
two years ago, and it's never come back.

I agree with you that it shouldn't make a difference, & I wouldn't be surprised if
this doesn't work all the time, but all I can say is that on this occasion, it "fixed"
their problem.

The theater was operating on a very tight budget, so if this hadn't worked, they
probably would have just left the pixel on screen. In fact, I never even billed
them for my last minute late night 'emergency' call, so as far as I'm concerned,
they got they're moneys-worth.
(Although I recently did another emergency job for them which saved them from
loosing a sold-out show, for which they paid me almost double what I billed them,
so "it's all good".)
 

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Posted by Marcel Birgelen (Member # 6801) on 03-12-2019, 02:36 PM:
 
Well, maybe it was just showing 14 hours of "moving images" that did the trick eventually.
 

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Posted by Stephan Shelley (Member # 8587) on 03-13-2019, 06:22 PM:
 
Yes mark I know one can install Barco test patterns in an NEC. I have done it as well. The issue is that NEC does not seem to have the alternating checkerboard and on the Barcos I have checked it is not a PNG file but seems to be internal and not something one can download.
 

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Posted by Mark Gulbrandsen (Member # 72) on 03-13-2019, 07:17 PM:
 
Exactly Stephen, NEC does not include that type of file. I wonder of there is an equivelent video file that could be put on a server and looped for playback over night???

Mark
 

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Posted by Kieran Hall (Member # 10268) on 03-14-2019, 11:21 PM:
 
We had a stuck red pixel on our CP2000 last summer, and fixed it with something similar. We weren't aware of the checkerboard pattern at the time, but as a last-ditch effort we made a DCP (in DCP-o-Matic, without any colourspace conversions) that flashed 100% DCI-P3 red for 1 second and then black for one second, and then looped it overnight. We were quite pleasantly surprised when it actually seemed to work!

I guess this achieved something similar to what the flashing white of the checkerboard does (i.e. 100% on, 100% off alternating), but only on the one DMD.
 

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