CP650 Dolby Digital Not Working Anymore

[Kyle Mikolajczyk]

So our CP650 decided to stop processing Dolby Digital a few months ago. Every time we run a print with DD it immediately reverts to Optical. I thought the reader might be having an issue (2 DP70 projector setup with Kinoton digital readers) and connected the reader up to an old DA20, and it appears to be decoding fine on there. What do you think could be the issue with our CP650? It works fine for AES, non-sync, and external 6 channel, although as I said in an older post it does freeze up now and again.

[Mark Gulbrandsen]

If this is the original LED check that first as well as the video level coming in. It's common for segments in that LED to fail as they get older if you can hold an ND filter in front of it, then it will be obvious. . If it turns out not to be that, then there is a problem in the cable, or processor. I can honestly say that I have never had the DD section in any 650 fail I guess It's possible. Quite a few failures in CP-500's and DA-20's though...

[Kyle Mikolajczyk]

Thanks for the tips Mark. I will check the readers but neither seem to be doing anything for the 650. The DA-20 like I was saying showed signs of life when it was being used through the LEDs and indicator display.

[Alan Lyman]

I would also check the error number on the DA20,and if it finds all the corners of the block.those two very well indicates if the LED on the reader is bad or misaligned.
Alan

[Gordon McLeod]

Connect your scope to the CP650 and see if it is receiving any video data.Try reseating all the cards

[Marco Giustini]

If the DA20 works, then it has to be the 650 - what do you mean with ‘signs of life’ though? Do you see a decent error rate?

what does the error rate say on the 650 when you play? Does it show ‘-‘ or any other characters?

did you try the second input of the processor - that would need the changeover to be changed though.

if you have an oscilloscope, that would give you more clue. Anyways removing the top board and reseating then daughter board which is plugged on top may help too.

remember never to plug the sound head when the processor is switched on BTW.

[Kyle Mikolajczyk]

Marco,

The CP650 doesn't seem to show any indication that DD is doing anything. Neither input works, both have the same effect of nothing.

I opened the CP650 and removed all cards, and then removed the top board from the daughter board and reseated everything. There still appears to be no difference. Tried the DA20 again and it does more than the CP650. I am not familiar with the DA20, but here is a short video of what the panel shows (I have yet to look into how to make an audio cable from the DA20 to the CP650). I appreciate all the ideas!

[Marin Zorica]

Take both manual and make cable from DA20 output to CP650 6ch input,also you should do automation so that DA20 triggers 6ch input when there is dolby digital run and triggers back format 5 (sr) when dolby digital is missing. Both are db25 connector, only check in manuals for pinout. If DA20 is going for rate 5 and decosing than 650 should do something as well, because i don't think rate 5 in da20 could be rate - in 650,so that 650 revert. Also did you try other pribts as well? Is it same rate on DA20? If not, dolby digital decoder cat 773 could be a problem in CP650,but check on 650 display is there any error rate displayed or just "-". But even witb that, some other problem in cat773 can be a issue, only way to check out is to try swap cat773 from some other 650 for test.

[Marco Giustini]

Have you got the right projector selected on the 650 when playing? Can you take a video of the 650 as well? Do you see the 773 recognised on the ‘about’ menu of the 650?

just plugging your head to the other connector won’t work as you also need to tell the projector to look for ‘projector 2’.

[Gordon McLeod]

Have you tried running the software dras

[Sam Chavez]

Added to making sure the correct projector is selected, what are you running for test film? Easy and obvious but if the film is not running in the forward direction, it will show as normal but will not output actual audio. I notice the DA20 is showing no audio output on the Cat. 611 signal presence indicators.

All else fails, I have lots of new Cat. 773's and would be happy to loan you one.

[Steve Guttag]

Sam brings up a great point. Do you have the Motor sense lines properly connected? The reason for the the Motor sense jumper when they ship is to ensure that M1 is always one for platter houses. However, for changeovers, you do need to provide a motor sense line for each projector. Without that, neither the DA20 nor the CP650 will output Dolby Digital audio.

[Marco Giustini]

Well I brought that point first

[Steve Guttag]

You brought up the changeover (selecting the right projector)...i didn't see you mention about the motor sense lines.

[Marco Giustini]

I was referring to when you mentioned that Sam brought up a great point

Have you got the right projector selected on the 650 when playing? .

Added to making sure the correct projector is selected

Just banter of course!