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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » CP500 Digital Subsystem failure (Page 1)

 
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Author Topic: CP500 Digital Subsystem failure
Ken Lackner
Phenomenal Film Handler

Posts: 1875
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 07-19-2004 12:26 AM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
When playing one of our prints in SRD tonight, I noticed that the dialog was very choppy, as if the actors were talking into a fan. This was accompanied by a very high error rate, fluctuating between 7. and F. Cleaning the reader did not reduce the error rate. I switched the processor to SR, and the sound was fine. I left it in SR for the rest of the show.

I decided to reboot the processor before the next show. Same problem. Switched to SR, and again it was fine. This time I decided to reset the digital subsystem. While it was resetting, a message appeared on the sceen saying, "One or more of the Dolby Digital modules have failed! System will attempt to recover." [Eek!] A trip to the Event Log revealed that both of the Cat. 671 cards and the 673 have failed. After the show, I turned off the processor, pulled and reset all the cards, powered on, and reset the digital subsystem. The error message appeared again.

Several questions on this. Are the high error rate and the distortion related, are they two seperate problems, or is there no way to tell? If the error rate was constanly fulctuating between anything and F, why did the front panel not show a reversion? At first that is why I thought the sound was so crappy, but it was staying in SRD the whole time (until I manually switched it).

How likely is it that all three of these cards will fail at once? Has anyone had this problem before? If the cards have failed, why does digital work at all? In general, what causes a card to fail?

Why does the error message only show up on screen when I reset the digital subsystem, but not when I reboot the CP500? In the Event Log, there are only entries for the 671 and 673 failures when I reset the digital subsystem. The only entry when I power on the processor is the standard power on entry (I forget the exact wording). I never would have known about the card failures if I never reset the digital subsystem, especially because all the LED's were lit normally. I wish that message would show up when I turn on the processor so that I would know about the problem sooner.

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Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000


 - posted 07-19-2004 03:38 AM      Profile for Antonio Marcheselli   Author's Homepage   Email Antonio Marcheselli   Send New Private Message       Edit/Delete Post 
Ken

Someone will be more useful than me but when you reset the digital subsystem it is normal to see entries in the event log. And, in my experience, I was used to see, sometimes, error events in my old CP500! I had my CP revert to BYPASS twice in two days once, on the event log there was "illegal operation". I thought that someting wrong was happened and that the unit would be required service.

Never happened again.

Bye!
A

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Gordon McLeod
Film God

Posts: 9448
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 07-19-2004 10:14 AM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
The distortion is most likely the chopping effect of the system rapidly toggling between analogue and digital

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Ferdinando Innocenti
Film Handler

Posts: 79
From: Genova / Italy
Registered: Jun 2004


 - posted 07-19-2004 06:40 PM      Profile for Ferdinando Innocenti   Email Ferdinando Innocenti   Send New Private Message       Edit/Delete Post 
If you reset only the digital subsystem is normal to have the "one or more digital...". I think because the system is not reloaded, so something is missing. I use software version 1.50

It's possible that your CP500 has revertions so fast that the display is not able to show them in real time.

Ciao
Nando

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Rick Long Jr
Expert Film Handler

Posts: 211
From: Toronto, Canada
Registered: Jul 2000


 - posted 07-19-2004 09:00 PM      Profile for Rick Long Jr   Email Rick Long Jr   Send New Private Message       Edit/Delete Post 
Any time you reset the digital subsystem this message will show up. It will also log to the event log as if the cards failed because as far as the mother board is concerned, they went off for a sec, and therefore thinks they have a problem. This is normal. When you do a cold boot (power off) the mother board resets as well.
I've found most problems with the SR-D system in 500's can be cleared by simply reseating the cards, or checking the reader alignment. Thats not to say card failures don't happen, but usually it's the 670 or the 673 I've found go.

The distortion and the high error rate/block errors are indeed connected.

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Ken Lackner
Phenomenal Film Handler

Posts: 1875
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 07-19-2004 09:22 PM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
If these events (the error message and the entries in the log) occor every time the DA20 is reset, then how do I distinguish between a "normal" reboot error, and a genuine card failure?

If these errors are not pointing to a card failure, as I thought they were, then I assume that is why I am getting digital sound? (Remember, I originally asked why I would get sound if all three of these cards are bad.) Any ideas what else could be the problem?

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002


 - posted 07-19-2004 09:54 PM      Profile for Manny Knowles   Email Manny Knowles   Send New Private Message       Edit/Delete Post 
Could be:

(a) The Print
(b) The Reader
(c) Cabling?
(d) Cards in the processor

Let's forget what the Error Log says and assume for a moment that we know NOTHING about the cards. I had this problem before and here's what happened:

The symptom was the alternating 7-F Error Rate and the intermittent digital/analog. I suppose there are some situations that don't trigger a solid reversion, but that's another issue.

I figured I would adopt a procedural approach to this problem, starting with the print, then the reader and the cabling and finally on into the processor.

I ran a brand-new trailer between shows and got a good playback. This suggested that the system was in good shape, so I decided to cross-check the print on another system. The problem followed the print.

Assuming that I could not get ANY film to play properly on the system in question...and let's say my questionable print checked out okay on another projector...then I would have hooked up my test gear and ran some test film to see if my reader had possibly fallen out of alignment.

After checking the reader, I would then move onto the processor and see if one or more cards had died.

In this particular case it turned out that my print was at fault. The whole print was scratched in the SRD area. I decided to run a loop and see if the damage was still happening or if, perhaps, this was a one-time offense. Nope. My test loop was getting scratched -- I watched the error rate go from 2 all the way up to....7-F...within about 5 mins of looping.

The gate had not been cleaned on a regular basis. The film bands developed a "burr" from film dust and that burr was tough enough to scrape emulsion from the SRD data blocks.

I cleaned the bands but they were in bad shape. Ended up being a replacement situation.

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Ken Lackner
Phenomenal Film Handler

Posts: 1875
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 07-21-2004 01:09 AM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
Here's an update.

First, I reset the DA20 on my other two CP500's. Sure enough, the same "error" ocurred, along with the same three entries in the Event Log. At this point, I'm thinking it's almost certainly not a processor problem. So I decided to follow Manny's troubleshooting process.

I moved the suspected print into a house where I normally get an error rate around 2 to 4. It played at 7, with an occasional "bad block" LED, but it never went to F (at least not while I was watching it). I went into the auditorium to listen to it. I didn't hear the distortion. But the very high error rate still leads me to believe that the problem is with the print. Also, the print that I moved into the other auditorium (the house where I originally suspected a bad processor) was playing at 4.

Now to try to find out what damaged the print. I made a loop from a brand new trailer and ran it through the projector for about 10 minutes. It played at 4 the whole time. Never went up. Perhaps the culprit was removed from the film path. Or it could have been somewhere other than the projector head, such as the brain or platter rollers. I still cleaned the gate and trap thoroughly (they were very nasty) and all the rollers, including the ones on the platter.

Why would a brand new trailer start out at such a high error rate? I know 4 is still acceptable, but I would think a brand new print would run at 1 or 2.

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002


 - posted 07-21-2004 01:23 AM      Profile for Manny Knowles   Email Manny Knowles   Send New Private Message       Edit/Delete Post 
I've usually had lower error rates with trailers (than with features).

Could be you need a fresh reader alignment. Then your "bad print" might run constantly at 7 instead of 7-F....?

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Ken Lackner
Phenomenal Film Handler

Posts: 1875
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 07-21-2004 01:26 AM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
Unfortunately, that is something I do not have the equipment, the know-how (yet), and most importantly the authorization to do. It'll have to wait until my tech comes for PM.

Out of curiosity, what is there to align? I'm familiar with doing an A-chain on an optical head (my last tech showed me how to do that), but I don't know about aligning digital heads. I didn't think there was anything to align.

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002


 - posted 07-21-2004 01:41 AM      Profile for Manny Knowles   Email Manny Knowles   Send New Private Message       Edit/Delete Post 
Most common would be a voltage adjustment to the lamp. The physical settings tend to stay put.

Other things that could cause problems would be focus, azimuth, magnification and lateral adjustment. With the exception of focus, these don't tend to "drift" out of alignment.

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Ken Lackner
Phenomenal Film Handler

Posts: 1875
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 07-21-2004 01:44 AM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
quote: Manny Knowles
Most common would be a voltage adjustment to the lamp.
I knew about that. I didn't really associate that with "alignment." I thought alignment meant just the physical things, such as what you described.

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 07-21-2004 02:37 AM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
It is all in the CP500 manual. Even with pictures!

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Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000


 - posted 07-21-2004 04:00 AM      Profile for Antonio Marcheselli   Author's Homepage   Email Antonio Marcheselli   Send New Private Message       Edit/Delete Post 
Ken,

If your print reads 7 with few error block on another projector probably your reader is just slight out of alignment.

Be sure that the LED is clean and the sound drum is free of dust. Then, if the problem is still there with the same (and other prints), you probably just need a new alignment!

If you had the Cp650 newer software has the capability to show the LED voltage on the screen, so you don't need any special tool (if the reader is already weel aligned of course!)

ByeA

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002


 - posted 07-21-2004 12:05 PM      Profile for Manny Knowles   Email Manny Knowles   Send New Private Message       Edit/Delete Post 
Don't forget some earlier readers have a white light (not LED). [Big Grin]

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