This is topic Dolby CP500 Problems in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Paul Rich (Member # 243) on 12-08-2000, 10:07 AM:
Three of our eight CP500s are having the exact same problem. They switch in and out of digital. When it's in SR and you press the digital button, it says "Not Ready" and has a circle with a line through it and will not let you switch it into digital. It goes in and out of digital randomly. Any help would be appreciated.
Posted by Michael Cunningham (Member # 210) on 12-08-2000, 01:22 PM:
These may seem like really obvious suggestions, but they are the things I would try first. Have you cleaned your sound optics? By this I mean your exciter / L.E.D., slit lens or barrel lens (if reverse scan). If you're using a penthouse style reader for SR-D you should clean the same components. How is your buzz track (lateral) positioning? Digital is far more sensitive than analog to things like proper alignment. This wouldn't be applicable with a penthouse, but is the reader bolted on top of the projector straight? Lastly, how is the ouput voltage to your exciter / L.E.D.? Low light levels can lead to this kind of behavior though you may have to have your Technician look into this for you. As a last resort, I would also ask your Technician about proper azimuth / focus of your SR-D reader. I hope these suggestions give you something to work with. Also, providing these film-techers with more information always seems to help (ie. type of reader, L.E.D. or white light, placement on projector, etc.)-Mike
Posted by Scott Norwood (Member # 30) on 12-08-2000, 03:53 PM:
I'm much more familiar with the CP50 and CP65 than the CP500, but does the 500 have an error-rate display like the DA20 does? (I don't have the 500 manual handy and I don't have time to download it here.)
If you _do_ have an error counter, what does it display? Is it something like 7-F-7-F or 2-F-2-F-2-F? The latter might indicate an alignment problem, while the former usually indicates a bad print.
What kind of SR-D readers are you using? Do you have the penthouses (like the SDDS reader) or the basement readers?
Is the cable connection between the SR-D reader and the CP500 good?
Posted by Steve Guttag (Member # 268) on 12-08-2000, 04:42 PM:
Me thinks one should look at the error meter in the CP-500 (yes Scott, just like the DA-20). My guess is that it is running high with a bunch of "F"s....IF this is the case and your optics are clean, my guess is that your illumination source is low (either EPT lamp or RED LED). If this is the case and it is the LED, you really need an O'scope to properly set the level (either penthouse or basement). You can try and goose up the LED level a bit to see if it helps until your tech comes by (assuming the company that you work for allows you to tamper with such settings).
Steve
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"Old projectionists never die, they just changeover!"
Posted by Rory Burke (Member # 512) on 12-08-2000, 07:16 PM:
Quick Check:
Make a big loop using a brand new trailer.....and run it through the machine.......look for two things......
While running the trailer in the projector open the face of the CP-500 and look to the top righthand portion of the unit. You will see about9-11 cards sitting vertically with all sorts of lights and techno goodies.
1. Youll see a number counter displaying a red munber ( 1-7 ) of the letters F E or a -.
If your digital unit is working properly (comparing to the theaters that work fine)youll see the numbers 1-6. The moment it drops out into SR youll see 7/F, 7/F. F =fail. That is a hint you need an A-chain performed immediately.
2. You also have six groups of tiny little green lights that should be illuminated bright and sustained while digital is working properly. A sign of trouble is when those lights are flickering and blinking like a Disney Electical Parade <Bows in memory>. You also need an A-chain if this is the case.Rory
Posted by Paul Rich (Member # 243) on 12-08-2000, 10:06 PM:
We checked one of the units, and the error rate display showed 4-F-4-F etc. We'll check everything mentioned and see if it helps. Thanks.
Posted by Randy Stankey (Member # 64) on 12-09-2000, 12:02 AM:
What reader do you have? How long have they been running? How long ago did this start?When it's running, is the light in the reader head red or white?
If it's white, how long has it been since the "exciter" has been replaced or checked?
If it's red, would it be fair to say that you've had the thing for about 1 to 1/2 years? (more or less) Would it be fair to say that it started a few months ago but it only happened "once in a while", now it happens almost all the time?
If so, I'd vote for a bad LED. Your tech could probably get you going "temporarily" then order a new LED for you. He'll just raise the LED voltage until the reader is back in spec. The LED will keep getting worse on you and it will have to be replaced. That's why a new one needs to be ordered right now. (Most companies take what seems like AGES to order things!)
You can't do this stuff "by eye"! You have to have an oscilloscope and know how to use it. It isn't "hard" per-se, but you have to know what you're doing.
On the other hand, if the light is white, go get yourself a new "exciter". The bulb is an "EPT'. It looks like a slide projector bulb. (In fact, I think it IS...)
It'll take you 10 minutes to replace.... 90 seconds to replace the lamp but 8 minutes and 30 seconds to go downstairs find it in the usher's closet! 
Posted by Brad Miller (Member # 2) on 12-09-2000, 01:49 AM:
Paul, please give us as much information as you possibly can on your readers (penthouse or basement). If basement readers, what brand of projector and reader? There are so many things that can cause this we will need more info on your setup. Even something as simple as a bad set of bearings in the sounddrum on a basement reader will cause 4-F-4-F-4-F-4-F.
Posted by Rory Burke (Member # 512) on 12-09-2000, 10:20 AM:
4f 4f 4f 4f 4f is a bad sign. The only solution is a complete A-shain. It could be power supply output. LED alignment...camera focus problems...camera azimuth problems...etc....cal a tech to come out and check your digital a-chain and in the mean time run the movies in SR only...These digital drop-out problems are easy to fix easier to prevent and honestly is a typical sign of when to be alarmed due to the theater's ill practice of preventative maintenace and scheduled maintenance procedures.Rory
Posted by Mark Wright (Member # 390) on 12-11-2000, 12:23 PM:
I have noticed one thing on any SRD unit! If you are reading any number error rate then fault then it keeps switching and have tried all of the good things(which are very important) that people have mentioned to do to the unit and it still does not work. Oil the rollers, It sounds to simple but it works very good and helps from keeping the fault pop up if it is in aligned and sorts also. Make sure you do not get the oil on the roller were the film would toucn it. ------------------
Posted by Richard Hamilton (Member # 321) on 12-11-2000, 06:36 PM:
Hey Paul, Did this just start in all 3 auditoriums? If the CP500 says "not ready", then it isn't seeing any digital information. When you try to manually put the processor in digital, are you sure that there is good digital information? What kind of projectors are these? Are you sure that its an SRD print? Does the problem print run O.K. in an auditorium that you know runs a digital print fine?Rick