Film-Tech Forum ARCHIVE: BACP DSTR-20 Problem

This is topic BACP DSTR-20 Problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by John Cruz (Member # 6531) on 10-23-2011, 01:11 PM:

Hi,

First and foremost, thanks for accepting me to the forum.

Now to the issue.

Our theater recently got two CP650's and two DSTR-20's from another theater the company owns. We didn't have digital sound in two theaters, so we installed the processors and soundheads. Unfortunately, one of the soundheads didn't work right from the start, giving off almost constant "F"'s even on new digitally mastered film. I know for a fact that neither the processor nor the Video Cable are at fault in the theater where we get the reverted sound signal.

I read in the forum that the voltage may be too low, and that by cutting one of the jumpers the voltage could be increased. I checked and the jumper was already cut. The alignment of the LED was not off either (I tried re-positioning it in every possible way to no effect). The lens is obviously clean as well. I wanted to check the actual voltage read-out on the CP650 but it has really old hardware (not sure which one, but it still allows for Dolby E).

To make matters worse, one of our less experienced projectionists messed around with it and somehow was able to kill the LED. From what I understand, he plugged in the jumper cable into the wrong connector and it got fried. At least almost everything was tried before this happened (I hope) so it is not the end of the world.

Should we consider getting a new LED/Heatsink module or would that be a bad idea since the projectionist incorrectly connected the jumper cable?

Any help is appreciated.

Thanks!

Posted by Tony Bandiera Jr (Member # 2365) on 10-23-2011, 02:08 PM:

Hi John, welcome to the forum. [Smile]

First off, you will need to get a competent tech in there to fix this, after you fire the "less experienced projectionist" who has blown out your LED power supply.

The DSTR-20 is a solid penthouse reader and will fail to read only when it is improperly adjusted. (Are you giving us the right model number? There are NO jumpers on the DSTR-20 that need to EVER be cut!!)

The one and ONLY user adjustment is the LED current trimpot. Set it as described in the manual, or do it this way: with no film in the reader, turn it up until the light turns orange, then slowly back down until the light just turns green.

If you have given the right model number, your tech will need to order up a new LED/Heatsink module, and a replacement LED driver board.

The tech will then have to re-align the reader using an oscilloscope to get you running again.

And I repeat that to prevent future problems you need to fire your less experienced projectionist...or better yet, take the cost of the service call and parts out of his/her paycheck.

Posted by John Cruz (Member # 6531) on 10-23-2011, 05:43 PM:

Thanks for the advice. Taking action against imprudent attempts to fix expensive equipment is definitely a good idea, but unfortunately I don't think we have the benefit of doing that. Business isn't great, and we have a three man crew. The head projectionist just left, and now it is up to myself and another projectionist who has been here for a while to keep the place from going under. Our new guy started less than a month ago, and received about 2 weeks worth of training. Not that many "experienced" projectionists will take a job, since it barely pays over minimum wage. It also takes time to train new projectionists, and temporarily running a 6 screen theater with 2 projectionists gets really tough.

Anyways, we will call in our tech and try to get him over here to fix the problem. The cowboy attempt to fix the problem was probably prompted when we were told that the soundhead was junk and that a new one should be ordered. (Is it the case that a soundhead should be discarded when it starts to read F, or is it simply a matter of replacing the LED or making alignments?)

Unfortunately our tech services many theaters and can't stop by unless we have an emergency that requires us to cancel shows.

We do have the DSTR-20 soundheads. I was reading up on the issue and possible solutions in the forum and came across cutting jumpers and likely got confused.

I hope it is ok to ask a few more questions regarding some "minor" issues we are having in the forum (granted they have not been addressed in other posts), since we really don't have anyone else to rely on. I really appreciate the help.

Thanks,
John

Posted by Louis Bornwasser (Member # 3063) on 10-23-2011, 06:53 PM:

One of the few advantages of a "penthouse" is that it can be sent off for repair. The factory or a good shop will make it new again. "Touched for the very first time,. . . . " Louis

Posted by Tony Bandiera Jr (Member # 2365) on 10-23-2011, 06:54 PM:

John:

Before anyone else chimes in, I would say that ONE man (with ONE relief man) is enough to run a six-plex. [Smile]

I have run ten screens in a cinema with four separate projection rooms without even breaking a sweat. Train your folks well, thread up in frame and take a few extra seconds at threadup and before pushing the start button to double-check things and I can promise you will rarely, if ever, have problems. You will actually get bored by the down time between show starts.

And I am not trying to bust your balls, but I am strongly against allowing ANYONE in a booth who can't leave things alone when they have no clue what they're doing. (On the other hand, if I was the tech servicing your theatre I would gladly continue to come out and bill you for the damages.) Trust me, the lost shows and revenue from such a clown will quickly exceed the cost of a proper service call. Especially with business not being great, you can't afford any downtime from incompetence. And if you are the manager or responsible for booth operations, and you don't reign in the troublemakers, you will soon be looking for a new job.

Advice column over, now to the other points:

Soundheads are too expensive to throw out for the simple reason it isn't reading right. ALL of the critical parts on most soundheads are easy to replace and align to get it working right again. Now if the projector/soundhead was crushed by a steel beam, involved in a fire or something like that, well... [Big Grin]

Edited to add: What Louis said above is great advise and may be your best bet.

You are more than welcome to come here and ask whatever you want, just read the FAQ's, don't post teaser titles, and try to put your questions in the appropriate forums. (Also try doing a search with keywords from your question, you may find a thread that already has your answer in it.) There are a LOT of very experienced and helpful folks here and you'll learn a lot. [Smile]

Posted by John Cruz (Member # 6531) on 10-24-2011, 08:39 AM:

Thanks so much again!

I think sending in the busted soundhead is the best alternative. I don't know why our tech would have suggested getting rid of it. Just recently we decomissioned a Cat. 701 because it wasn't reading properly and got a "new" soundhead in its place. Now it is just sitting in our booth for spare parts.
Our theater is quite old, so maintanence seems to be a daily thing. People never took out booth seriously I think, so it is in bad shape. I was reading the other day that oil should be drained completely from the intermittent and replaced. Last time I saw my tech I asked him when the last time this was done and he said never. There are small other things that have gone undone for ages, so something is happening all the time.

Our tech is on retainer and should ideally be coming in once a month for preventive maintanence, but unfortunately that doesn't happen so it is left for us to do.

Good advice on the soundhead. I'll post some additional questions soon.

Posted by Sam D. Chavez (Member # 1841) on 10-24-2011, 09:06 AM:

There may be some gain links on the CCD camera board Dolby Cat. 1054.

They should not be touched but if it makes you feel better, it was probably DOA to start.

You can do a repair return with either USL of BACP. It's $500 flat fee to get it back in shape, or you can try to find another.

Main thing that kills these is hot plugging the video cable. Usually kills the CCD card, or the front end of the cinema processor.

Posted by Tony Bandiera Jr (Member # 2365) on 10-24-2011, 05:23 PM:

To expand on what Sam said, "Hot plugging" means connecting OR disconnecting the video cable with the processor powered up. You must have the processor OFF (the red light in the power button lit) before dealing with the video cable!!

Posted by John Cruz (Member # 6531) on 10-25-2011, 12:03 PM:

Thanks for the clarification. Luckily my tech gave me a heads up on that when we were putting in the CP650 and the Sound-head. Just out of curiosity, does this practice apply to Dolby Cat. 701 sound heads as well (we have 701's and dstr-20's in our theater)? I know there is a power switch on the sound head, unlike the DSTR-20. Would turning off the power to the Cat. 701 suffice, or should the processor always be turned off as a rule of thumb? Adjustments to the sound head require it to be powered down, is that correct?

Posted by Tony Bandiera Jr (Member # 2365) on 10-25-2011, 01:24 PM:

John: The power-down the processor rule applies to ALL digital readers, regardless of type. The 701 (and 700, 699) readers power switch ONLY turns off the light source, it has nothing to do with the CCD camera (which is what the processor connects to.) The BACP reader's LED is powered through the video cable (a neat thing actually) and a tech can add a power switch to a BACP reader's LED if needed. (I did at UC Irvine as the processor stays on 24/7 but I did not want the LED's running when I'm not running films.)

Most adjustments to the soundhead require it to be powered ON to get readings.

Replacement of ANY electrical or some mechanical parts would need a power-down. (You can swap the LED module on a BACP hot, but I don't recommend it.)

Posted by John Cruz (Member # 6531) on 10-25-2011, 02:10 PM:

Thanks, I appreciate the feedback!