This is topic Dolby CP500 glitch? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Joe Redifer (Member # 3) on 03-13-2000, 02:31 AM:
I have a CP500 that occasionally produces a "ticking" or "clicking" type of sound from the surrounds, which can also be easilly heard from the sound processor outputs of the booth monitor. The only way to get rid of the defect is to reboot. This happens maybe once every 6 months or so at random.A little history about this CP500: Early on in it's life it would drop completely out to silence no matter what sound format it was playing. Completely at random. I thought that perhaps it was the analog output card, so I switched cards with another CP500 in the building just to see. The CP500 that I put the bad card into crashed a few months later (no sound, unable to restore) and the entire unit was replaced. Now this one just reproduces crackling sounds from the surrounds every once in a while. Software has been upgraded recently to 1.61ex. Anybody heard of anything like this?
Posted by Andrew D'Vrey (Member # 285) on 03-13-2000, 03:25 AM:
Wow, we had that exact same thing happen about 6 months ago. It sorta fixed itself so I haven't thought about it much since. And in my case, yes...it came out of the surrounds only. I did power-off/bypass and power-on and the problem disappeared. Happened one other time too much longer ago. Haven't had it happen again since.
I tend not to be too processor savvy. Especially on the CP500. I looked at the purchase invoice, saw those big numbers and decided to let someone else take their chances screwing it up 
.
But yes, I believe I had the same problem. I may do a service call if it happens again and will post my findings.
------------------
"And the monkey flips the switch."
- Major Don West, "Lost In Space"
Andrew D'Vrey
IATSE Local 219
Posted by David Kilderry (Member # 142) on 03-13-2000, 03:29 AM:
Yes, CP500's are prone to this fault. We have had about 3 units produce this clicking in the surrounds on various occasions, a reboot solves the problem yet we cannot reproduce it on demand to track the fault!
Posted by Joshua Lott (Member # 240) on 03-13-2000, 04:19 AM:
I have heard a popping or cracking out of the surrounds in several theatres on different occasions and only in the houses with CP500's. I was told that it is probably static. I also have noticed that sometimes when I start a movie (in 3 different houses) it will stay in non-sync. Non-Sync is in User 1 mode.
Posted by Joe Redifer (Member # 3) on 03-13-2000, 06:24 AM:
Stays in Non-Sync? Hmmmm, I have this problem as well, but only occasionally. The problem worsens when I hook up the logic cable between the CP500 and the Dolby SA-10 EX adapter.What's up with the CP500? Welcome to the world of digital control!
Posted by Joshua Lott (Member # 240) on 03-13-2000, 07:13 AM:
I only have this problem occasionally too. But no EX 
and it only happens in 3 auditoriums, I have 11 that have CP500's. I wonder what is going on here?
Posted by Ken Jacquart (Member # 369) on 03-13-2000, 06:18 PM:
Regarding CP500 and crackling audio...
Check out Field Bulletin 220. In a nutshell, there is a potential chip problem of IC6 on the Cat. No. 675A when operating at higher temperatures in slots J12 and J14 (Matrix decoder and EQ). This may affect a range of circuit board serial no.'s 11500 to 16700. If this fits your scenario, let me know and I'll send you a new chip (it's in a socket... easy).
Posted by Joshua Lott (Member # 240) on 03-13-2000, 06:22 PM:
I will check into this next time at the theatre. It's nice to see someone from Dolby here at Film Tech.
Posted by Joshua Lott (Member # 240) on 03-17-2000, 01:22 AM:
I have now checked into this. It seems as is the serial number of the unit itself is in the 500,000 range and the 675 card is 84,000. Any other suggestions. These units are at a bran new install. Less than a couple of months (3 to be exact).
Posted by Devriendt Miguel (Member # 296) on 03-17-2000, 08:00 AM:
Hello everone,
You guys aren't the only one with troubles with the cp500's.
Recently we have bought 3 new ones.
And when we installed one it would run, when we looked inside the cp500, we saw that the main board wasn't plugged in, but was pressed inside so that the board comes nexto the plugs.
An other one was playing for 3weeks, and one day i'm truying to turn the volume a bit up. Strangly al he did was going down. I pressed the on the options to see what it does on the LCD brightness, and als here i get the same result, it goes down and it won't goes up.
Result level is ending on 0 and there no question on turning it back to 7.
Rebooting, digital reset, nothing helps.
We had to play in bypass.
Has anyone had the same experience once?
2 of 3 cp500 aren't good.
What's wrong with dolby?