my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » DTS timecode drop out/TCR LED switching (Page 1)

This topic comprises 3 pages: 1  2  3

Author Topic: DTS timecode drop out/TCR LED switching Dominic Espinosa Phenomenal Film Handler Posts: 1172 From: Boulder Creek, CA. Registered: Jan 2004 posted 01-19-2006 04:44 AM                     Greetings all. Did a quick search but couldn't turn anything relevant up. I'm having an issue with our DTS house not reliably detecting timecode on all prints. It started being an intermittent problem about a month ago but I figured it an abberation. I cleaned the print, checked the LED voltage and put it back in spec, no problem. Now it's on every other print the timecode just will not read reliably. I've made sure all the rollers in the film path from the center feed to the first sprocket in the projector are properly aligned and the film motion is smooth and steady. The film is hitting the rollers on the reader dead on. Adding the film cleaner to add tension to the film doesn't seem to affect it either. What should I try next?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-19-2006 04:52 AM                     Put a scope on the readers output and verify that the signal is actually a good clean signal. There is a DTS technical bulletin on this and I think that bulletin shows up in some of the manuals (don't have it handy at the moment). If the signal is clean, it is your player that has the issue. Remember, the green LED on the reader is actually activated by the DTS player, not the reader (pin 9 on the DB9 connector on the reader). Steve  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-19-2006 08:24 AM                     also check the version of the TCfirmware as it will affect the reading of certain prints  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-19-2006 08:27 AM                     But first..... while you have the readers cover off and before you check the signal quality with a scope(or use the scope on DC setting) set the pot in there for 4 volts dc across the test points. If this voltage is too low... below about 2.8 volts it is not a high enough signal to run the player reliably. This adjustment is done without film in the reader! If you can't get it to at least 4 volts then the LED needs to be replaced, typically they can adjust up to at least about 4.8 or 5 volts in level, but the factory setting is 4 volts. Also, lately I've had a rash of time code readers that have drums that are worn too wide allowing the film to weave back and forth as its being scanned and causing the time code level to go high and then low and so on. Its easy to find these bad drums... just place a piece of LaVezzi Stainless steel film around the drum and look at the side clearance, or use a caliper with long measurement tangs. There should not be any clearance at all on a good drum with the steel film in there. Out here we have the unfortunate situation of inheriting a bunch of locations that were installed by a now defunct equipment dealer... and he either did not align them at all or did a very poor "eyeball" alignment on them when they were originally installed...... They need to be carefully aligned due to the bare alumnium scanning drum which is relatively soft material....  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 01-19-2006 07:56 PM                    I was told WE cant replace the LED in the DTS readers, but rather the entire unit has to be sent in to DTS to repair. Is this true? or is this extortion? They mentioned something about very fine and precise adjustments that need to be made.  |  IP: Logged Daryl C. W. O'Shea Film God Posts: 3977 From: Midland Ontario Canada (where Panavision & IMAX lenses come from) Registered: Jun 2002 posted 01-19-2006 08:01 PM                        quote: Frank Dubrois I was told WE cant replace the LED in the DTS readers That all depends on your definition of we.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-19-2006 09:43 PM                     The LED is replaceable if you a have a source for them have the shop to do it and align the reader  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-19-2006 10:00 PM                     Both gord and I do LED replacements. The 250 plus dollar cost of a R/A'd time code reader from DTS is absolutely rediclous for the sake of an LED! quote: Frank Dubrois Is this true? or is this extortion? Frank, Its very close to extortion! In fact the actual reader is pretty close to that itself even when brand new. Nice CNC machining quality but EXTREMELY poor choice of materials for a piece that gets that much daily use. It certainly guarantees DTS perpetual repairs for as ling as film is around... or at least for as long as that TC reader is around. Mark  |  IP: Logged Dominic Espinosa Phenomenal Film Handler Posts: 1172 From: Boulder Creek, CA. Registered: Jan 2004 posted 01-20-2006 04:43 AM                     After some much due fidling today I got it to run in digital throughout my test pack of trailers, some as old as 4 years with the timecode light staying fairly solid. It's still not perfect however. As I don't have the experience nor an oscilloscope I won't be able to do much else on my own. I am however curious about the procedure mentioned above. Am I correct in assuming that you would be monitoring the signal pin from the TCR's input on the processor? Or am I totally off base?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-20-2006 09:12 AM                     No, Remove the cover on the time code reader. You must have a simple inexpensive digital volt meter around there... if not they cost a whole 20 bucks so go get one...... You will see two small test points. The blue one TP-1 is minus and the black one TP-2 is positive...if memory serves me correctly but if I'm backwards just reverse your leads. Set the small white potentiometer R-16 so you read 4 volts DC across those test points WITH NO FILM IN THE READER! This is as basic an adjustment as it gets..... You would also connect the scope to those same test points and see this signal which is what good time code looks like.....  |  IP: Logged Daryl C. W. O'Shea Film God Posts: 3977 From: Midland Ontario Canada (where Panavision & IMAX lenses come from) Registered: Jun 2002 posted 01-20-2006 12:33 PM                        Mark... quote: Dominic Espinosa I cleaned the print, checked the LED voltage and put it back in spec, no problem.  |  IP: Logged Benjamin J. Kepner Film Handler Posts: 15 From: Muskegon, MI, USA Registered: May 2002 posted 01-20-2006 03:44 PM                     Anyone happen to have specs on a proper replacement LED for these? Anyone tried installing a different color LED? Just because red is so depressing of an LED color. Or possibly just a slightly brighter LED just so that you could adjust it down and get a bit more life out of it (LED should nearly last forever anyway, don't know why these crap out as much as they do).  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-20-2006 05:16 PM                     The LED's that Gord and I are using are ALOT brighter than the DTS LED's. They also have a much longrer life span than DTS's LED does. So yes, I have to adjust them down in brightness which means an even longer life span than the LED manufacturers specs. Getting these higher quality LED's entailed Gord and I ordering a rather large batch of them which we split. The only other thing I can tell you is that I charge 100.00 flat to replace it... far more reasonable than what DTS charges. Mark  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 01-20-2006 07:01 PM                    Whats the process of replacing the LED? Is it a simple unsolder/resolder job? For $100, I would suspect there was more to it, but taking on the liability of potentially ruining the reader must be built into that cost as well.  |  IP: Logged Brad Allen Jedi Master Film Handler Posts: 688 From: Evansville, IN, USA Registered: May 2000 posted 01-20-2006 07:12 PM                     And the cost of having money tied up in a large stock of the LEDs.  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1  2  3

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.