Pink/green stripes

[Bene Gabor]

Hello,

We use a Christie CP2215 and a Dolby DSS200. There is a problem shows up occasionally, sometimes right on the beginning of the show, sometimes just during the film. The problem is that pink and green stripes come up on the screen or lots of tiny dots flash/vibrate. It could happen, too that the show just goes black. Temporary solution is the restart, but not so good because it has to restart over and over again to make it work properly. The problem comes up both in 2D and 3D (XPAND active) shows. Any idea what cause the problem?

Gabor

[Steve Guttag]

When picture anomalies show up, the most likely culprit (particularly the kind that come and go) is the ICP module. Reseating it can often cure the problem. We've taken to also using DeOxit on the card to improve its chances.

Please note, this will trigger a security event for which you'll need the ability/knowledge to clear a marriage tamper.

Sometimes, when testing for the problem, pressing in on the ICP card will temporarily "fix" the problem. Another troubleshooting tip is to put up a test pattern (preferably one with a mix of colors as well as some black and full white. If the test pattern is clean, odds are the light engine is fine and the ICP is fine (you can still have noise on the ICP's input) but the test pattern cuts the signal path in half. If the problem is there with the test pattern, nothing before the ICP could be causing it.

[Marcel Birgelen]

I agree with Steve, primary suspect is the ICP and re-seating (and remarrying / clearing the tamper alert) is the first thing you should try. It's also the cheapest fix if it works.

Another potential culprit could be the media block. Do you have the possibility to run some external content? And if so, did you ever notice the same problems with this content?

[Bene Gabor]

Yes, we experienced this in most cases when we play 'non-factory' dcps (like adverb we make with DCP-o-matic).

Gabor

[Carsten Kurz]

The DCP mastering software is irrelevant there. Make sure you control data rate and frame rate to specs. No more than 200MBIt/s, keep it to 24fps frame rate (or 30fps if necessary). Many sources nowadays are 50 or 60fps, and most projectors will not play these, or not without artifacts.

If you observe this often with ads, the reason may be that during preshow the projector may not be heated up, and a contact problem could go away later during main feature. It could also be the other way round, of course. But very often this type of problem is solved by a card reseating.

- Carsten

[Marcel Birgelen]

Yes, I wasn't really referring to self-generated DCPs, but rather external content via HDMI, as this doesn't take the path through the mediablock. If you have the same issues with this content, you can exclude the mediablock or rather the entire DSS200 as a potential culprit for your problem. It's always good to eliminate some potential sources of trouble when looking for the cause of a problem.