Projection QOTD

LavaASU

Active Member
Would a mod mind moving this as it seems we cannot post in QOTD anymore.

Since this is a bit tougher than most... perhaps students and people that aren't professional projectionist for the first week would make more sense?

This is a 3 chip DLP projector thats unhappy.

PJ error checkers.jpg

Image 1 shows what should be a black and white checkerboard test pattern with a menu on top
PJ error black.jpg


Image 2 shows a black internal test pattern with a menu on top

1. Whats missing?

2. Whats there that shouldn't be?

3. What part is causing this problem?

4. Where would you (if you were going to be working on it) start looking?

Note: I've already fixed this so this isn't a help me thread. I just thought it was kinda interesting and would give people an interesting challenge. Theres a bit more to this that I will post in a few days but it gives away answers to these questions.
 
Looks to me like the green is displaying some image that is not changing. I guess the first place I'd look is for a connection issue between the green chip and the controller.
 
Looks to me like the green is displaying some image that is not changing. I guess the first place I'd look is for a connection issue between the green chip and the controller.

Yep, it was displaying the trees image (yes, they're sideways long story unrelated) when it glitched and green stayed on that and the red and blue kept responding.

So who wants to guess what connection was lost to have this happen?
 
Its been 3 weeks so I think this is safe to comment.....
What is feeding the projector? That looks similar to an issue on a 2K dcinema unit I was asked to troubleshoot back in November. Everything had a red overlay, except the red in the test patterns.
Solution to that one was interesting, and in my opinion, not satisfactory as it did not address the root cause. It turned out the IMB board had come loose from the backplane, causing spurious signals to confuse the ICP board, which resulted in the red overlays on all inputs and the ICP board's internal test patterns. The service company had to come out, use the secure key to open the projector, reseat both boards in the backplane, and then re-arm the crypto engine and remarry the two boards once all the tamper seals were reset.
 
Yep, that BS being why I have zero interest in dcinema projection. They break enough without adding things intended to make them break.
As a consumer, I choose not to purchase any media with effective DRM (I don't mind it nearly as much when applied to freebies and rentals). Thankfully the music industry seems to have gotten over its facination with DRM, but I fear it will be a much longer road before (if ever) the film industry accepts that DRM does more harm than good (hindering use of paying customers while failing to actually reduce piracy).
 
So I guess I will give the answer. It was the power connector to the green formatter board that was loose. So the green formatter (and DMD) lost power while showing the image, andtherefore did not have time to reset. Generally with a signal loss the formatter would reset/default and clear the image.
 

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