This is topic Need Help with DA20 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Dean Kollet (Member # 1789) on 12-08-2003, 09:52 PM:
 
After 6 months in booth, I'm starting to learn how to fix stuff. Well, actually, when something breaks I try to fix it by looking on here; usually finding it in a manual (thanks guys). Well, the booth manager is switching jobs and he is just bombarded with stuff, so I'm trying to help out and fix stuff. It's turned into a hobby really. Here's my problem

Strong Nighlight II Lamphous
Strong Projector
Simplex 5-Star Soundhead
Ultrastereo 35mm Processor
Dolby CAT 700
Dolby CAT DA20

We have a Dolby DA20 on a Cart (to switch between theaters) that hasn't worked for months. I ran two Dolby test loops through (I forget the CAT #'s but they were the Dolby Tone and Speaker Identification ones). I get 6,7,F the whole time while nothing plays out of the speakers. Everything seems to be working except the output of the signal back to the processor. As far as hooking up stuff and check frequencies, I'll do what I have to do, and I know it's a hard thing to troubleshoot but I want to learn and no one @ the theater can show me b/c they don't know. Plus, this could show management that I'm eager/devoted enough to go for more formal technical training. Oh yeah, BTW, they let me do this stuff , as long as the theater is empty and I'm not doing something extreme...they seem to appreciate my hard-work. I don't want people to think I'm like sneaking around and whatnot...

Thanks a lot everyone!! I'm learning a bunch of stuff and hope to learn even more..
 

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Posted by Manny Knowles (Member # 1171) on 12-08-2003, 11:18 PM:
 
Sounds like a reader head alignment might help.

Do you only get an occasional "F" or does the error rate actually fluctuate in a 6-7-F pattern?
 

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Posted by Rick Long Jr (Member # 541) on 12-08-2003, 11:25 PM:
 
I'd try changing the Cat 700 exciter lamp first.
 

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Posted by Manny Knowles (Member # 1171) on 12-08-2003, 11:40 PM:
 
Yep. That would certainly be the easiest thing to check and it could well put the unit back into service once again.

Still, I would want to carry out an alignment for the benefit of knowing that it is performing at its optimal level. Especially since this is an inherited situation. I'd need to "lay hands" on the thing and "cast out the demons."

I'd be interested in knowing what it tracks after a simple bulb change.

I don't have experience with the older SRD heads so I'm wondering if there would be dramatic reduction of errors or just a bump up to, say, 5..?

Does anyone think that this is a problem with the DA-20 (as the thread title suggests) and not a reader issue?
 

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Posted by Dean Kollet (Member # 1789) on 12-08-2003, 11:41 PM:
 
I forgot to mention, we have two of those carts and the other cart works in this theater fine...
 

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Posted by Manny Knowles (Member # 1171) on 12-09-2003, 12:03 AM:
 
Well, then...in that case...

Let the card swapping begin!

Be sure to kill the power to the units before inserting or removing a card.

One card at a time.

Be careful to return each card to the correct DA20 after testing.

If you get the faulty one to work by swapping in a card then you've probably bullseyed the cause.

I like to cross-check by trying out the suspect card in the working unit and seeing if the problem is duplicated there. (I wonder if others do this, too.)
 

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Posted by Brad Miller (Member # 2) on 12-09-2003, 12:31 AM:
 
How many rollaround racks do you have with DA20s in them?

How many cat700 readers do you have?

The first thing you should do assuming you have at least two readers is to hook up the "broken" DA20 into the "known to be good" cat700 and see if it starts working. If so, you have a bad cat700. If not, it's something in the DA20.

Always start with the big items first, THEN start working with the smaller stuff (like swapping cards) second.

Like Manny said, be careful when you swap cards. Don't force anything. Get yourself a grounding strap so you don't damage a card from static. Also, put a small piece of tape on the corner of every card from the "known to be functional" DA20 so you don't get things confused and can put it all back.
 

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Posted by Dennis M Dow Jr (Member # 1970) on 12-09-2003, 05:08 PM:
 
Brad said

quote:

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The first thing you should do assuming you have at least two readers is to hook up the "broken" DA20 into the "known to be good" cat700 and see if it starts working. If so, you have a bad cat700. If not, it's something in the DA20.

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quote:

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we have two of those carts and the other cart works in this theater fine

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That would tend to rule out problems with the reader. Leave it alone for now.

One thing you might check is what happened to me recently. Get a meter & measure the 5 volt power supply test point. If it's off, read this.
 

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Posted by Dennis M Dow Jr (Member # 1970) on 12-13-2003, 02:36 PM:
 
If everything checks out you might want to check the cables you use to connect to the unit to the processor
 

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Posted by Stephen Jones (Member # 16) on 12-13-2003, 06:28 PM:
 
My rule regarding faults or problems that arise that I am not sure of and rather than stabbing in the dark with the possability of making things worse a quick call to our service people who are more than willing to help over the phone with any problems I may be haveing and 99% of the time the problem is fixed this way.Also they advise if its a dont touch prob and needs a tech with the equipment to do the job which is rarely required and if it is then we book the job in to be done.By doing this our equipment is always in good condition and we rarely have major problems after all its what these guys are there for and over the phone help is free.Even after 33 yrs in projection things still arise that I am not sure off.

Steve
 

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Posted by Manny Knowles (Member # 1171) on 12-14-2003, 04:46 PM:
 
What on earth are you doing mixing it up with the likes of us?

Obviously we can be of no use to you and, evidently, you aren't prepared to offer much to the rest of us...

Just curious about that.
 

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Posted by Gordon McLeod (Member # 33) on 12-14-2003, 04:53 PM:
 
I think Stephen has raised a very valid point Manny and one I wish alot of other people followed If you are unsure of something in your workplace it is prudent to check with the people that your employer wants to be used to maintain and service the equipment before proceeding on ones own into the dark. I believe you actually said that about the training of your own companies operators and the level of troubleshouting they were allowed to do
 

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Posted by Manny Knowles (Member # 1171) on 12-14-2003, 05:15 PM:
 
Yes, Gordon. Acknowledged. But I leave room for the possibility that there are folks out there who (a) have no-one to turn to and/or (b) are authorized to turn to "outsiders" for help.

As for the projectionists working in our booths, I don't set the policy although I do happen to agree with it. Furthermore, I think you would agree that are certain prerequisites to servicing projection equipment and, let's face it, most of today's multiplex projectionists don't meet those.

I was genuinely confused by the post because it seemed to imply that turning Film-Tech was a bad idea.

There have been times when I was faced with a problem that was beyond my level of comfort and experience and, still, I posted the query for two reasons:

1. My tech might find the input helpful; and
2. Someone else might have the same problem later on.

So I would have no problem with one of my own projectionists visiting Film-Tech and participating in the forums so long as they honored the terms of their employment agreement, which basically says "don't try to fix or modify the equipment in any way."
 

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Posted by Gordon McLeod (Member # 33) on 12-14-2003, 05:19 PM:
 
Manny said"I was genuinely confused by the post because it seemed to imply that turning Film-Tech was a bad idea."
I couldn't read that in to what was said at all
 

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