Film-Tech Forum ARCHIVE: Dolby CP650 switching formats by itself

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Posted by Michal Matys (Member # 8614) on 11-06-2015, 07:23 AM:

Hi guys,

Strage thing started happening on one of our CP650.

During the screening, the format changes by itself to Non Sync. There is no cue sent from server or any other device. It is 3 years old instalation, and there were no recent changes made on this setup, so I have no idea where its comming from. It is completely random, happenes like 3-4 times a week.

Anyone experienced this issue before?

Thanks
Michal

Posted by Magnus Eriksson (Member # 6085) on 11-06-2015, 07:59 AM:

Anything connected to:
1) Ethernet
2) RS232
3) Automatation (DB25)
If so, disconnect these one by one and see if anything changes.
/M.E.

Posted by Jim Cassedy (Member # 4115) on 11-06-2015, 09:50 AM:

Is there a DMA-8 in your system?
A couple of years ago I had a similar problem, and it
turned out that the fault was actually in the DMA-8,
which was occasionally sending erroneous random format
change commands to the CP-650.

As Magnus suggested, you'll need to disconnect any
external 'trigger' devices from the CP-650 and run
a few shows without them and see if you still have
the problem. In my experience CP-650's have been
really stable devices.

Posted by Ken Lackner (Member # 1002) on 11-06-2015, 10:32 AM:

I had the same issue a few months ago. The problem started when I plugged the CP-650's power cable into a UPS rather than directly into one of the outlets in the rack. Turns out there was too much load (I assume) on the UPS and the CP-650 was rebooting. It was configured to boot into non-sync, rather than "last format selected," so every time this power glitch occurred during a movie, the CP-650 reboot and went to non-sync.

Even if you don't have a UPS, if none of the other troubleshooting steps above reveal the source of the problem, it would be worth it to move the power cable to a different outlet. However, if you happen to be standing in front of the CP-650 when the issue occurs and you see that it just switches to another format and you don't observe a reboot, then power is not your issue.

Posted by Michal Matys (Member # 8614) on 11-06-2015, 10:50 AM:

Hi Guys,

Thanks for those fast answers!

There is no DMA-8 installed. I unplugged the ethernet this morning, it was first the first idea Ive got, so we will see if it will happen again when its unplugged.

The thing about the power source is actually interesting, I will tell the projectionist to try to "catch" the moment. Maybe it can be power supply issue when it will restart itself, what do you think?

Posted by Ken Lackner (Member # 1002) on 11-06-2015, 11:06 AM:

If you observe the unit reboot on its own and you know the outlet it is plugged in to is good, then I would try swapping the power supply with another 650. Of course, the chances of catching it are incredibly rare unless you have someone sit in front of it all day.

Posted by Carsten Kurz (Member # 5396) on 11-06-2015, 12:00 PM:

Try to set up a camera.

- Carsten

Posted by Scott Norwood (Member # 30) on 11-06-2015, 12:14 PM:

Do you have one or more cat. 779 remote control boxes installed? If so, disconnect them. Among other possibilities, I have seen odd things happen with multiple cat. 779s if a unique ID is not set on each.

Posted by Tony Bandiera Jr (Member # 2365) on 11-08-2015, 12:39 PM:

If this continues and none of the good advice given above works, try this:

Power down the processor, disconnect the power cord, remove the front metal panel and pull and reseat the boards, also pull and reseat the ribbon cable connections to the front panel. Replace the front panel and power it back up.

And to expand on Ken's post... a bad power cord (or loose connection at the processor or receptacle end) can cause the processor to reboot as well.

Had that issue with a CP200 on a service call many years ago...a flaky connection at the receptacle end would kill the power just long enough for the CP200's logic to think it was waking up, it did the same thing, kept switching format to the "D" preset at random.