Film-Tech Forum ARCHIVE: CP500 total sound loss ??

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Posted by Jason Black (Member # 684) on 12-20-2003, 06:56 PM:

Here's a problem that we just had with one of our CP 500's.

3/4 of the way thru the R5, a customer informs my usher that sound just went out in #10. The operator got to the unit before I could and he could not get any response out of the unit. He actually had to power the system down and reboot it then all was fine. All cards seemed seated properly and this print has played in this house since tuesday night with no problems. It runs a consitant 2 - 2.5 timecode rate...

Any ideas on what I could possibly check into as to what may cause this total lack of output? There was no Optical nor digital and he also noticed that there was no intermission music.

This same unit has had this problem before and I've never been able to figure out exactly what causes it. It is sporadic, only happening once every few months or so and a reboot will ALWAYS solve the problem.

I can't figure this one out so I'm turning to you guys for help... [Confused]

Posted by Gordon McLeod (Member # 33) on 12-20-2003, 07:33 PM:

WHat version of software is running and does it loose its setting after the reboot

Posted by Michael Schaffer (Member # 1204) on 12-20-2003, 07:52 PM:

The most likely cause for this would be overheating, I think. It might be interesting to see if or to what extent the signal path for optical and digital in the CP500 is still intact, if you have time to check these quickly before rebooting.

Posted by Antonio Marcheselli (Member # 373) on 12-20-2003, 08:11 PM:

Was the Bypass led on? Did the sound come back when you push the bypass/power button?

Bye!
A

Posted by Jason Black (Member # 684) on 12-20-2003, 09:10 PM:

Gordon,

I'm not sure of the software version. I recall it was updated once. From what I remember Lonny Jennings telling us, we had some of the first CP500's released in the US market. I don't know of a way to check the software version while the unit is active...
I don't understand what you're asking when you mention loosing it's setting after the reboot?

Michael,

I'm unsure how far the signal path travels up to teh point of loss, and I also don't kno whow to check it. Unless it was something that was really fast to check, I wouldn't have time, as I try to keep any downtime to a minimum. I don't think it'd be an overheating issue, or it seems it would occur on a more frequent basis. I don't notice any internal extremes in temperature, but I also know that electronic components can be very quirky to say the least.

Antonio,
I'll have to post a note to check that on the next occurence. I'm really not sure... as I say a complete reboot does clear up the probelms, but a reboot, in and of itself, takes about a minute or so... [Frown]

Posted by Ken Layton (Member # 133) on 12-21-2003, 01:42 AM:

Did the liquid crystal display go out also?

Posted by Michael Schaffer (Member # 1204) on 12-21-2003, 03:43 AM:

It probably plays no role here for this problem, but in general, it is quite easy and rewarding to learn how to follow the signal path, especially in the CP500. Just refer to the block diagram in the back of the manual. I think the numbers used there are also mirrored inside the unit when you open the front panel.

Posted by Jason Black (Member # 684) on 12-21-2003, 08:37 AM:

Ken,

No, the LCD is still up.

Michael,

I'll have to download teh manual from the FT site. I couldn't find a manual at work. They all seem to have walked off.

Posted by Fabrice Dubourg (Member # 1635) on 12-21-2003, 10:20 AM:

maybe, the Cat 684 board got a problem, can you swap it with another processor ?

Posted by Mark Gulbrandsen (Member # 72) on 12-21-2003, 04:50 PM:

Dolby recommended that we place a batch of 500's that we had installed in a 8 plex on back up power supplies, and then to never power them down. These processors were loosing their settings from time to time and reverting to the default setting....which is basically no sound at all of any type. The backups cured the problem and needless to say has it never reappeared with the backups in there. Odd cure but the location was remote and the problem happened often enough to justify the solution. The particuluar version escapes me but it was a location using DA-10 EX adaptors.

Mark

Posted by Steve Guttag (Member # 268) on 12-21-2003, 05:33 PM:

The problem being described here isn't the dreaded CP-500 "Do you want to restore factory settings" screen of death (PS never say yes....just call your service tech and pray sh/e has a copy of your settings).

Since the factory default settings for the CP-500 were stupidly all of the way down on both the optical preamp and the output....upon reinitializing...you will be without sound on both bypass and regular audio (optical preamps will be all of the way down).

The memory dumping problem showed itself on firmware 1.5x and later...version 1.61 is the buggest one of them all (including the 1.61EX).

Since Mark's installation has an SA-Ten (EX) then I believe you would have needed 1.52 or 1.61(EX) to use it (only these versions would tell the SA-TEN to go out of EX upon an optical reversion).

If you do not have an EX adapter of some type...I strongly recommend going to version 1.31. It is quite stable and will not give you the memory dump.

If you do have EX...consider the 1.52 version...1.61 is known to ignore occasional "Non-Sync" pulses from the automation.

FWIW...on the CP-650 ... version 2.0.10.8 is my personal favorite but it does not know about the new crossover or the 5-screen channel thing. Stay away from version 1 anything on the CP-650...aside from the potential memory dump some of the early ones had other bugs. I've yet to come across any version 2 bugs.

I think the CP-500 in this case either has a noisey connector or an intermittent problem on one of the DSP boards. The symptoms are what appears to be a "lock-up" This is not a normal CP-500 failure. Another big clue is the huge space of time between failures (month or so). You can RXO the whole CP-500 if you don't want to find the source of the problem or you can use another CP-500 within the facility (if you have one) to card swap until the problem moves. Beware, the Cat. 684 (the main board)...which is most likely the cause also has all of your EQ and level settings on it so swapping it will also swap you tunings.

Steve

Posted by Paul G. Thompson (Member # 655) on 12-24-2003, 12:09 AM:

The only time I was faced with this problem is when a ceiling water leak got into the CP-500 and graced itself all over the main board. The CP-500 blew its brains out. Ken Layton remembers that one....I was the butthead that had to get it running after Dolby sent me a new main board.

Other than that, the CP-500 has been solid as a rock.

Posted by Fabrice Dubourg (Member # 1635) on 12-27-2003, 06:50 AM:

have solved your problem ?

Posted by Jason Black (Member # 684) on 12-27-2003, 10:59 AM:

Fabrice,

As I stated in my initial post, the problem is very intermittent. It might happen once every other month. It has occured twice in a 2-3 week span but then it didn't happen again for months. As stated, it always locks out during the show, never in 'down time'. My operator has to power it down and reboot it, then every thing is fine. I will swap out the Cat 684 and see if the problem follows as I do have 4 other units but I'm waiting until after our business subsides from the holiday rush to do so...

I downloaded the manual and brought it to work as well. The software version I have is 1.31, so it looks like I've never had any updates?

I did just check teh event log and noticed that the Cat 675 in J12 has failed a few times. Could that be the problem?

Posted by Steve Guttag (Member # 268) on 12-27-2003, 01:54 PM:

Remember, if you move the Cat. 684...you are moving your levels and EQs with it.

Stay with version 1.31...it is the most stable of the CP-500 firmwares.

Steve

Posted by Jason Black (Member # 684) on 12-27-2003, 03:21 PM:

Steve,

Thanks.. I have two houses built to exact specs (dimensions, seating, equip, etc..) Do you think that swapping the 684 between these two houses will make a huge difference in the EQ array? Seems to me that they shoudl be EQ'd out real clsoe to identical... but I'm not a tech... [Smile]

Also, any advice on the cat 675 failure? I skimmed teh manual, but found no refernece to it...

Posted by Steve Guttag (Member # 268) on 12-27-2003, 06:55 PM:

As to the EQ difference...you can't get two identical rooms to come out the same but they may be close enough. Depending on how your service is set up...doing a simple brain dump of each and a reload will allow you to transpose the settings. Mind you I'm not telling you to do this. This is what I would do. The same can be accomplished by moving the proms but when troubleshooting, you want to disturb the least amount.

Steve