Film-Tech Forum ARCHIVE: Christie CP-2000SB grey stripe flashing issue

This is topic Christie CP-2000SB grey stripe flashing issue in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Michal Matys (Member # 8614) on 11-27-2014, 03:52 PM:

Hi guys!

I have an issue on Christie CP-2000SB projector.

During the screening, there is occasionally grey stripe, like some kind of noise. I have checked the HDSDI cables, replaced them, it looks fine, the server is fine as well.

Here you can see how the problem looks : https://drive.google.com/file/d/0ByfoPqRH5HPtZEgwb191M2FnN0k/view?usp=sharing

Do you think it will be the Interface board? Because the problem was on this projector like 2 years ago (When I was not working there) and I have been told that they have tried toreplace the Interface board and the problem persisted.

If you have any ideas i will be happy if you could share.

Thx!

Posted by Marco Giustini (Member # 4544) on 11-27-2014, 05:08 PM:

Have you recorded interstellar? [Smile]

It seems an encryption problem but I have never seen it "half screen". That snow usually happens when you open the projector and the encryption is disabled.

What server are you using and what are the software versions installed (server and projector)?

- make sure the software is up to date, on both server and projector (watch out for "DCI only" software, your Christie may now support it and you CANNOT downgrade it). Make sure the TI board software is up to date (15.1)
- Check for HDSDI errors. Cannot remember on top of my head where it is but it is called SMPTE-something and errors must be zero at all times. If they keep rising and you have already replaced the HDSDI cables, then the input board may be defective
- how did they sort out the problem last time?

Does it happen only with encrypted content? Does it happen constantly? Does it show up with test patterns as well? Does it happen on DVI sources>

Posted by Steve Guttag (Member # 268) on 11-27-2014, 06:10 PM:

Christie has a Tech Bulletin on some types of image flash/break up for the Series 1 projectors.

One problem for ALL Series 1 projectors (any brand) is on the "B" HDSDI line where if the signal is too strong, it will cause errors...it is recommended that for any series 1 projector that the cable length be 50-feet of RG-58 to achieve a desired amount of attenuation without attenuating the signal too much.

If you have the ability to monitor the SMPTE error rates...clear the errors and then look at the error (particularly of the B channel)...it will rise but note if during the periods of the flashing if it rises at a great rate...this would be a clue.

Christie notes that if you have an input on a DVI connector that IT may be causing interference with the HDSDI signal. Try removing it or, if possible, moving it to the other input.

Christie notes that the sort of problem they've seen is normally corrected with the change of the motherboard...failing that, the interface board.

Given the age of the projector (the last SBs came off the line in 2009), don't rule out connectors and mere contact oxidation or other like issues. Merely reseating the right cable may take care of it.

Posted by Michal Matys (Member # 8614) on 11-28-2014, 02:37 AM:

Hi guys

Thank you for your answers.

When it dissapeared the first time, It just stopped showing by itself, which is strange. I will have a look at the software versions when I will be at the site.

The problem is happening aswell when there is no signal going through the HDSDI cables, I mean when you eject the movie and have just turned ON lamp a ond opened dowser. I did not see it on test pattern but that just might be a coinsidence.

There server we are using is DOREMI DP2K4.

The issue is happening constantly like every 20 minutes, sometimes more sometimes less, like half a year back it happened once a month, but it did not dissapear and they had to restart the projector everytime, and for last 3 months it did not happen once, just started this week happening a lot. I have swapped the server there recently but it can no be the issue, because it was doing it with the server before and this server was 100% ok on other hall.

Thank you

Posted by Marcel Birgelen (Member # 6801) on 11-28-2014, 03:01 AM:

Keep in mind with those serial signals: even if you're sending a black signal, doesn't mean you're not sending a signal at all. A signal carrying a fully black image has the same bitrate as everything else, even if the payload bits are essential all zeroes. (Which won't be the case, because the encryption layer in between will make sure it won't be just zeroes that go over the line [Wink]

).

Also, where did that test pattern come from? From the server or from the projector?

Posted by Marco Giustini (Member # 4544) on 11-28-2014, 03:23 AM:

Steve has a good point here, I forgot the hdsdi issue with early Christies. Let us know how it goes.

Posted by Michal Matys (Member # 8614) on 11-28-2014, 03:35 AM:

The test pattern came directly from projector, but I will check again if its happening during test patterns.

With the black image - the server content was ejected, that means there shouldnt be any signal going from server, right? I will try to check the error count on the B SMPTE.

Also I have noticed another strange thing, when you strike the lamp, during the "lamp strike electric noise" the screen which goes throgh VGA to server and is on the projector flashes as well, dont know if that has to do something with it.

BTW there is no DVI input used right now.