Film-Tech Forum ARCHIVE: DSTR-20 Soundhead video status question/Please help

This is topic DSTR-20 Soundhead video status question/Please help in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jason Gazaille (Member # 2846) on 11-26-2004, 12:46 AM:

We have these readers installed with our CP-650 Dolby processors. Some of them appear normal, video status indicators green, while others show red with even a brand new print playing. We have cleaned them, and have been told the alignment is good on them. The processor shows an error rate of anywhere from 0. and down and the sound is playing digital. The readers are a year in operation this week. This problem started to occur a little over a month ago. Does anyone out there know what could cause this? [Confused]

Posted by Steve Guttag (Member # 268) on 11-26-2004, 06:13 AM:

The "problem" is that the LED is faded. Cleaning your print will not help. What should be done is to turn up the LED current without film threaded until the status indicator turns green again. Note, you can adjust it with film threaded but it should be running...without the film running one of the digital blocks may give you a false "red".

Note, if you increase the current too much, you will get a combination green/red indicator that looks yellow.

Steve

Posted by Sam D. Chavez (Member # 1841) on 11-26-2004, 11:45 AM:

Thanks Steve, I cound not have said it better myself. Are you interested in a part time gig?

Posted by Steve Kraus (Member # 476) on 11-26-2004, 01:00 PM:

Just slip him a few bucks for answering questions he now does for free! [Big Grin]

Posted by Jason Gazaille (Member # 2846) on 11-26-2004, 01:38 PM:

Thanks, Steve, but sometimes we get that yellowish flicker between red and green, especially on our Movietickets trailer. Then, when the splice runs through, the status changes to red, regardless of how well the film plays and how new it is. Should the current have to be raised after only a year of service? Or could there be some type of problem with the electricity? We believe there could be in our building because of other things that have been happening, like slide bulbs going out in just a week, etc.

Posted by Brad Miller (Member # 2) on 11-26-2004, 01:43 PM:

Yes, raise the current. Your Movietickets trailer's SRD track was probably printed a little bit light.

On your slide projectors, run them on LOW position. There isn't much of a difference between HIGH and LOW output anyway and it will greatly extend the life of your bulbs. (By the way, is your booth hot? Are the slide projectors mounted in such a position that people physically bump them?)

Posted by Tony Bandiera Jr (Member # 2365) on 11-26-2004, 01:45 PM:

Jason:

Yeah, it's possible you have some power issues. Are you noticing the indicator's being red all day long or just at certain times of the day? And is it consistantly in the same houses? You may want your service tech to check the line voltages on the affected machines.

Posted by Jason Gazaille (Member # 2846) on 11-26-2004, 02:39 PM:

We do have our slide projectors on low, but since our auditoriums are so big, it does make a huge difference. People have refused to buy ads because they look washed out. The other theatres in our chain have the same slide projectors as we do and theirs run for months on one bulb on high.
Our booth is actually pretty cool.
While it is POSSIBLE for the slide projectors to get bumped, it is not likely as there is about 5 feet between the projector and the slide projectors. When I removed a bulb from number 1, it was cracked in half and the middle was melted and black.

As you all suggest, I'll make sure the currents get raised on those readers.

Tony-It happens all day on those machines. Also, our Christie lamps aren't lasting as long as they should, even with rotating. Also, the electric company said the power coming into the building was good, but the independent contractor we hired to check inside found voltage on the grounds.

I think it was a rep from Christie that told us it should be a few years before the current should need to be raised on those readers, though. Maybe I'm mistaken. Should they have to be raised after only a year, or is something causing them to go faster?

Posted by Darryl Spicer (Member # 711) on 11-26-2004, 06:02 PM:

Just a note in case you are not aware. That adjustment islocated behind the video board and lens assembly cover. It is held in place with four screws. You don't have to turn te adjustment a lot to get the signal to go up.

Posted by Steve Guttag (Member # 268) on 11-26-2004, 07:36 PM:

The LED on the BACP reader (and the Cat 702) is powered from the Dolby Digital processor (DA-10, DA-20, CP500 or CP650). The power supplies are regulated so there shouldn't be any voltage sag.

Next, LEDs fade from the moment they are turned on...after a year of use it appears that your LEDs are just on the cusp of being low since some film gets you a green. The whole purpose of the indicator is to let you know of this fade and so you can correct it BEFORE you have tracking issues. By your report, this is working perfectly...you reader is tracking but the clever reader has alerted you that you should make a minor adjustment at this time to avoid poor tracking in the future.

Note too, not all LEDs behave the same...some are fast fading, some seem to last forever and hold their level and I've had that rare bird where the level has gone up a little over time. In general, for me at least, I check on any LED that has been in use 3-months or more. I've found that the first three months (in a grind house) tends to get the fastest fade rate and then it becomes more gradual.

With the LED on Sam's reader and all new basement readers, this has taken the checking thing to a new form of ease since visually, one knows if the LED level is going to be just fine.

Furthermore, the indicator LED will allow you to run with the lowest current at all times and be in a safe-zone. With an O'scope you can set the LED for a video output of 4Vp-p...without film that is the point that seems to be just before you get the double red/green LED that makes yellow point. But, with the reader tracking so well, why not run the LED just in the green zone and prolong the LED's life since you have that handy indicator. It is such a simple thing and it is such a powerful tool. Thanks Sam, for that one!

Steve