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» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » DTS Problem. Time code drop outs (Page 1)

 
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Author Topic: DTS Problem. Time code drop outs
Mike Carro
Film Handler

Posts: 67
From: Tempe, Az USA
Registered: Nov 1999


 - posted 02-05-2004 12:15 AM      Profile for Mike Carro   Author's Homepage   Email Mike Carro   Send New Private Message       Edit/Delete Post 
I have a two drawer unit. It has been working fine until recently. The time code is not staying steady and drops out of digital. I tried tightening the tension but it doesn't do anything. I thought maybe it's the LED so , I have a spare reader and I put that in and... still the same problem. So, could it be a power supply issue? Any advice would be appreciated.

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Adam Martin
I'm not even gonna point out the irony.

Posts: 3686
From: Dallas, TX
Registered: Nov 2000


 - posted 02-05-2004 12:26 AM      Profile for Adam Martin   Author's Homepage   Email Adam Martin       Edit/Delete Post 
Is this with different prints or a single print is doing this?

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Mike Carro
Film Handler

Posts: 67
From: Tempe, Az USA
Registered: Nov 1999


 - posted 02-05-2004 12:45 AM      Profile for Mike Carro   Author's Homepage   Email Mike Carro   Send New Private Message       Edit/Delete Post 
Yes, different prints. It doesn't matter.

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Aaron Sisemore
Flaming Ribs beat Reeses Peanut Butter Cups any day!

Posts: 3061
From: Rockwall TX USA
Registered: Sep 1999


 - posted 02-05-2004 02:43 AM      Profile for Aaron Sisemore   Email Aaron Sisemore   Send New Private Message       Edit/Delete Post 
Do you have the latest ROM update installed [version 1.46]?

If you have a new enough reader, have you tried the reader LED calibration procedure ?

Has anyone tinkered with the lateral alignment screw on the reader (a definite no-no)?

All of these factors will affect timecode read performance.

If the LED calibration listed above doesn't fix the problem or you have one of the older readers without the LED voltage pot, you are likely going to have to get a reader on repair-exchange from DTS.

-Aaron

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 02-05-2004 02:44 AM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
Next step: perform the reader LED calibration. The instructions are on the home page here under public additions.
Oh - Mr Sisemore was 1 minute quicker than me. Maybe then I could add that you may find that your reader does not have the trimpot. Then you are doomed - you have to send it in.

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Mike Carro
Film Handler

Posts: 67
From: Tempe, Az USA
Registered: Nov 1999


 - posted 02-05-2004 08:55 AM      Profile for Mike Carro   Author's Homepage   Email Mike Carro   Send New Private Message       Edit/Delete Post 
I have older units. I don't think they have a trim pot. Where would it be located? And no, no one's tinkered withi it. they have a manufacture date of July '94. Could it be a problem with the CPU?
Okay and update;
My spare reader is newer than the other and it does have a pot. It was reading at 2v. I adjusted it. But it still does it. No quite as bad but it does drop out. Could the reader go out of allignment by itself? And is there a remedy?
If the green light on the reader goes on and off it means the reader isn't picking up the signal or does it mean the CPU can't read it?

[ 02-05-2004, 10:23 AM: Message edited by: Mike Carro ]

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 02-05-2004 11:14 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Ok, I beat both seismicmore and shlaffner by at least a minuite!

The pot is inside the time code reader. At the reader remove the T.C. cable with the power off! Then remove the four allen screws to expose the pcb inside. There might be a pot and there might not be one. I've seen em on older readers that have been modified or repaired in the past. No pot = A repair exchange for around 225.00 or so. You will get the new firmware 1.46 with the nre reader. be sure to install it if its not 1.46. You willalso get a bag of TCR mounting screws that includes the 70mm mounting stuff..... I suppose they have an excess of those to get rid of....

Anyway, if there is a pot them place your VOM probes on TP-1 and TP-2 and adjust the pot for 4 vdc with no film in the reader and no excess stray light hitting it either. Stray light does affect the reading. The reason for it going out of alignment is that the LED fades slowly over time. I find that if the DC setting is under 2.8 volts that things get pretty unstable. The green light is only an indication that TC is being read. Nothing to do with the CPU. You may also need to check your firmware which is located inside the unit. Foloow the DTS upgrade instructions on this site to see where to look for it.
Mark @ CLACO

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Aaron Sisemore
Flaming Ribs beat Reeses Peanut Butter Cups any day!

Posts: 3061
From: Rockwall TX USA
Registered: Sep 1999


 - posted 02-05-2004 01:04 PM      Profile for Aaron Sisemore   Email Aaron Sisemore   Send New Private Message       Edit/Delete Post 
July 1994? Those 'Jurassic-era' readers are likely goners by now especially if they saw constant use since then. By all means get new readers via repair/exchange, they will be freshly built ones with the adjustment pot in them.

Also if the firmware is a version HIGHER than 1.46, then 'downgrade' it to 1.46. The 'later' versions had some nasty bugs, and DTS actually went back to 1.46 and stayed there.

-Aaron

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Mike Carro
Film Handler

Posts: 67
From: Tempe, Az USA
Registered: Nov 1999


 - posted 02-05-2004 01:08 PM      Profile for Mike Carro   Author's Homepage   Email Mike Carro   Send New Private Message       Edit/Delete Post 
Thanks everyone. I've contacted DTS and they're helping me out big time. Thanks for all your help.

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Daryl C. W. O'Shea
Film God

Posts: 3977
From: Midland Ontario Canada (where Panavision & IMAX lenses come from)
Registered: Jun 2002


 - posted 02-05-2004 03:56 PM      Profile for Daryl C. W. O'Shea   Author's Homepage   Email Daryl C. W. O'Shea   Send New Private Message       Edit/Delete Post 
Having never seen the inside of an old reader. Is the only difference the addition of the trim pot (and possibly removal of a resistor), or is it an entirely different PCB?

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Bruce Hansen
Jedi Master Film Handler

Posts: 847
From: Stone Mountain, GA, USA
Registered: Dec 1999


 - posted 02-05-2004 05:28 PM      Profile for Bruce Hansen   Email Bruce Hansen   Send New Private Message       Edit/Delete Post 
Check to make sure that the film is going into the reader, and comeing out of the reader, and into the projector without twisting, or pulling to one side or the other. Is there any flutter from the projector that could cause jitter in the timecode? If you have a scope, look at the timecode. If you can move the reader and DTS player to another projector, you may want to try it.

By the way, I know what the LED alignment instructions say, but the pot does not adjust the LED voltage, it adjusts the gain of the opamp. You can put a volt meter accross the feed to the LED (the red and black wires soldered to the board) and adjust the pot. The LED voltage will not change.

Something for anyone having problems getting enough gain out of the opamp: clean the LED, and the solar cell that is on the back side of the board that is in the reader (you have to remove the board to get to it), and clean the optical path inside the reader.

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System Notices
Forum Watchdog / Soup Nazi

Posts: 215

Registered: Apr 2004


 - posted 07-04-2005 07:49 PM      Profile for System Notices         Edit/Delete Post 

It has been 515 days since the last post.


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Brian Hogan
Expert Film Handler

Posts: 119
From: Charlotte, North Carolina, USA
Registered: Jul 2001


 - posted 07-04-2005 07:49 PM      Profile for Brian Hogan   Email Brian Hogan   Send New Private Message       Edit/Delete Post 
i find myself in this same situation. our system plays fine for a few reels then it cuts out. ive been trying to trouble shoot and the problem is coming from the reader. ive been playing war of the worlds and the last 3 showings the reader cant read the time code for the last reel. it plays fine through the whole movie except for the last reel. im waiting on a multimeter so i can check the led voltage, but is it possible that it can happen? that possibly the whole print was clear enough for the reader to read, but then the last reel was maybe a bit tinted or something. just a bit darker so that a possibly week led could not transmit through?

ive had the same problem on mr & mrs smith. it would play fine for a bit then drop out. i dont know when exactly on that one, but i do on worlds. happens same spot everytime on it. any thoughts?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 07-04-2005 08:23 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Besides bad print/disks the most comon problem is the 4 volt adjustment in ythe TC reader. Place your negative probe on TP-1 and the positive on TP-2 and the meter should be on the DC volts scale to read 4 volts. Adjust the pot in there to read 4 volts WITHOUT FILM THREADED on your meter. If your TC reader does not have this pot or yopu camnnot reach the 4 volt level then you will need to get an R/A TC reader from DTS. Also, has your player ever gotten any upgrade of any tupe?

Mark

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 07-05-2005 08:55 AM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
Bruce said "You can put a volt meter accross the feed to the LED (the red and black wires soldered to the board) and adjust the pot. The LED voltage will not change. "
True it adjusts the gain of the opamp that provides the TC output but also a Diode and Diode including a LED will have a fixed voltage drop across it if silicon based it is around .7volts and around .3 volts if germanium. That is why a resistor must be inserries with a LED to limit the current

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