Film-Tech Forum ARCHIVE: Problem: DA-20 kicking cp-65 into A

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Posted by Scott Balko (Member # 438) on 08-07-2006, 08:33 AM:

I've got a DA-20 that upon wake-up will kick the CP-65 into Dolby A. Non-sync is selected manually for pre-show ads. Then when the first show is started, automation kicks digital but then it'll go back to SR and the digital light will go amber on the DA-20. Digital works fine but has to be selected manually. All shows there after run fine.

If the 20 is shut off separately leaving the rack powered, switching back on will put the 65 into SR and manual non-sync and digital are needed for the show following, then all works fine again.

Actually, I'm not sure if it's been consistent between SR or A on power up as it has done both. I haven't had that much time to note an exact consistency, but it will not let the processor stay in non-sync.

The 65 has been used off and on with DTS the last 2 years and has worked fine. The 20 has been sitting for awhile.(approx 4-5 years) All cards in the 65 and the 20 have been removed and reseated. All connections are new recently (4 days ago) and are tight.

I will try to give more info if needed. [Smile]

Posted by Steve Guttag (Member # 268) on 08-07-2006, 09:17 PM:

Boy, there are so many ways to go with this one. First off...odds are it isn't your CP65.

I've had issues with the Cat 611A doing strange things (that is the CP control card...the one on the far right).

I've had bad CP selector switch (the rotary one) so the 611A doesn't know what processor it is controlling (make sure your Cat 611A is set to correct CP...normally Position 2 for a CP65 if you want Auto-Digital).

The dreaded power supply connector can cause the DA20 to glitch a bit...it is the molex connector that comes out of the power supply "brick" and plugs into the mother board of the DA20. If the power rails sag due to this connector you are going to get strange performance.

I likely problem due to your unit selecting A or SR are this dumb resistors that Dolby UK insisted upon that have the DA20 select SR as a last gasp if a power supply dumps in the middle of the show...the problem is they false trigger the fall back.

Dolby has a field bulletin for the DA20 and describes which resistors should be removed/destroyed (they are SMT resistors). Refer to Field Bulletin 222 (I believe it is available here on FT in the Manuals section). Other Field Bulletins of interest are 190 and 226.

Posted by Scott Balko (Member # 438) on 08-08-2006, 08:54 PM:

Thanks loads Steve. We're looking into both these potential problems and I'll post back what we found.

Thanks again. [Smile]