Film-Tech Forum ARCHIVE: DTS: No timecode until reboot

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Posted by Antonio Marcheselli (Member # 373) on 07-24-2002, 05:29 AM:

I have a very strange problem with one of our DTS player. I've already wrote to Karen but I've decised to post here also because I believe that it is a strange thing and everyone's opinion is well accepted.

Here is my problem.

Readers are working properly, I checked them on my systemand I know that they are working perfectly. I found that there were installed not perfetly aligned with the projector, I've checked them, they still need to be slightly moved but during projection the timecode led bliks approx. 2 times for a minute. I believe that that shouldn't be a problem, right?

Let's come to the strange thing. We are projecting Resident evil. When the movie starts, timecode led stays COMPLETELY off, like there is no timecode track on the print or readers are completely misaligned. Only SYSTEM led blinks (as normal operations). Absolutely NO Blink on timecode.
But if I reboot the player (while projecting) the player starts to read timecode and switch in 6-ch properly. I also tried to do the following:

1. While player is NOT reading timecode, cover/uncover the reader's led with a business card. No effects, the player does not read anything from the reader
2. While player is reading correctly timecode (after the cold reboot) cover the reader's led with a business card. After 4.5 seconds the player drops to analog, but if I discover again the reader's LED the player read again timecode and switch in digital normally.
3. While the player is reading correctly timecode (after the cold reboot) cover the reader's led, let the player to drop. Then reboot th e player but this time keep covered the reader's led while the player is rebooting (simulating the start of the movie). No problem, when SYSTEM starts blinking I remove the business card and the timecode is read properly.

So, WHY I have to reboot (also open/close the cd drives) the unit at each movie's start????

Bye
Antonio

Posted by Karen Hultgren (Member # 395) on 07-24-2002, 12:57 PM:

Antonio,

This does not sound like a software problem.

First be sure that you cycle power whenever you change discs. This is very important.

Then, be sure that the voltage to the reader's lens is correct. Follow the procedure that I emailed you.

Be sure that all the rollers on the reader are in good condition and rotate freely.

Be sure that the projector's chassis is earth grounded.

Be sure that the projector's speed is correct and constant. You could have a problem with a slow or "bouncy" startup. Check to be sure that the projector's motor belt is not slipping.

Be sure film tension is constant. Position the reader's auxiliary roller as close to the large center roller as possible to achieve maximum film wrap.

Let me know what happens.

Karen at DTS
khultgren@dtsonline.com

Posted by Antonio Marcheselli (Member # 373) on 07-25-2002, 02:40 PM:

Karen,

Thanks for the post and email. Unfortunately I'm now come back to florence but I'll have someone make these tests.

But before leave I had a chance to make few tests and I have some results:

1. With no film threated I tried to connect the cable that come out from the DTS cable to the projector. Result: the green led of the reader become green (with no film running) but very dim.
While DTS film is running and timecode is read (after the power cycle) if I connect the ground cable to the projector the reader green led become very dim and the red "timecode" led on tha player turn off.

I didn't have a tester to test the projector ground. Do you believe that the projector isn't earthed and this can be the cause of the problem?

No problem with cycle power between two different disk: actually we have the same movie all the time on that screen.
And, I also tried to cycle power the unit before the show (say, 20 minutes before the start) and the timecode was not read at first attempt.

Projector is a Vic 8 that doesn't have belts.

Thanks for the procedure about how check the led voltage. But that readers came back from UK recently and has been used about 2 months since they've returned.

I think that projector earth has to be checked. Question: what connects the cable coming out from the dts cable? The chassis of the reader?

THANKS for your availability!

Antonio

Posted by Karen Hultgren (Member # 395) on 07-26-2002, 12:18 PM:

Antonio,

Use an ohm meter to check the projector. Go from the earth ground prong on the AC power in to the projector chassis. You should see zero ohms.

The projector chassis should be earth grounded separately from the DTS as should the sound rack. The DTS timecode cable (if it was made by DTS) comes with a ground strap tucked under the shink sleeving next to the 9-pin connector on the cable. If you need to earth ground the projector then you can use that strap. You would put it under one of the screws that connects the timecode cable to the reader. Just be sure the reader's chassis is common to the reader bracket. Then check that the reader's chassis is common to the projector. If the projector chassis is painted or heavily varnished, you may need to scrape away some paint/varnish to make a good connection.

You should check the reader's voltage to the LED. The readers you got two months ago are refirbished and may have new LEDs. In this case, during the first two months, the LEDs will pull down the voltage and then stablize. I'd check the voltage to the LED. I bet it is a little low.

I hope that helps.

Karen at DTS
khultgren@dtsonline.com

Posted by Antonio Marcheselli (Member # 373) on 07-26-2002, 01:42 PM:

Karen,

Thanks for your reply.

I didn't know that new LED has to be checked, I will check them and mine too!

quote:

If you need to earth ground the projector then you can use that strap. You would put it under one of the screws that connects the timecode cable to the reader.

I will check the projector earth, but I already connected the strip coming out from the timecode cable to the screw that secure the reader to the brackets. The result is that the green LED of the reader become green but very dim as I described before.

So, I'll check that projector is earthed. If not, I can earth it using the cable's strip but I need to check that readers is 0 ohm with the projector itself. Am I right?

Thanks for your help!

------------------
Antonio Marcheselli
Florence, Italy

Posted by Karen Hultgren (Member # 395) on 07-26-2002, 04:34 PM:

The grounding strap on the timecode cable gets its ground from the DTS player. Be sure that earth ground is common to the projector chassis AND sound rack.

Karen at DTS
khultgren@dtsonline.com

Posted by Antonio Marcheselli (Member # 373) on 07-26-2002, 07:02 PM:

Thanks Karen.

I've emailed detailed instrucions to my manager that have the player.
I hope that ground is the issue.

But why connecting the strip to the projector cause the green led to dim? Let's suppose that projector is not earthed, what can cause the green led to dim?

Thanks!

Antonio

Posted by Rick Long (Member # 213) on 07-26-2002, 10:37 PM:

A word of advice for anyone checking the led voltage. Blind old farts like me often use a flashlight to look for that pot. The light from the flashlight, however, affects the reading. Even ambient room light can have an effect (with the back of the reader off).

In short, do the setting adjustment with as little ambient light as possible.

Posted by Antonio Marcheselli (Member # 373) on 07-27-2002, 04:51 AM:

Thanks Rick for your advice!

Antonio

Posted by David Miller (Member # 412) on 08-03-2002, 04:19 PM:

And also, make sure you clean the reader head before you set the voltage of the LED. When I was setting one (of the 14 I did that night) I forgot to clean the lens and LED with a cotton swab. I cleaned it while my meter was still connected and got another 0.5 volts just by cleaning the reader. I'm sure you remembered, but just wanted to check.

David Miller
Technician, American Cinema Equipment

Posted by Don Sneed (Member # 955) on 08-03-2002, 05:53 PM:

Antonio, before you go to all that trouble, try this first....I too had to reboot 4-DTS-6D after a new install in Japan....thinking one can be bad, but ALL FOUR ??? I called Karen, she told me to do the same thing, I did, still had to reboot....I ordered 4-more replacement players thinking I had 4-bad players....one of our techs came to Japan (by mistake) so while he was there with me I asked him if he ever had this problem, he say he just had that problem, he solved it by cleaning the CD drive laser reader....DTS has a CD disk drive cleaner, which is a CD disk with a little tiny brush on the bottom side to clean the laser.....we did this, and all worked perfect thereafter, no more problem, we didn't need the replacement players after cleaning the laser reader...now if you get a disk drive cleaner fron DTS, the instruction say to run for 10 seconds.....that will not do, run the cleaner for 30-seconds in each drive, this solved the same problems you are having at three theatres, 8-DTS players....we now clean any player before we turn the theatre over to the owners...maybe this will be the same for yours...Good Luck !!

Posted by Paul G. Thompson (Member # 655) on 08-03-2002, 11:04 PM:

What's with all these DTS problems lately? Or, is it just me reading between the lines?

I am planning on purchasing a DTS unit here in the very near future, but I'll need one that is trouble free.

Very seldom do I hear any complaints about the DTS-6D that has two CD SCSI drives. But I, too, have had lots of problems with the DTS-6AD and the DTS-6 with three SCSI drives.

DTS has been vary gratious on their tech support department and corrected all of our problems. But I have noted yesterday that one of our roll-around units didn't feel like shifting into the digital mode until I re-booted it. What gives?????

Posted by Brian Tristam Williams (Member # 1235) on 08-04-2002, 12:33 AM:

Could it be a Y2K002 problem?

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"One man can make a difference."

Posted by Karen Hultgren (Member # 395) on 08-05-2002, 01:22 PM:

DTS does not have a Y2K problem. There are no clocks that the player ties to. The DTS-6AD does have a clock but that unit was released after year 2000.

DTS is one of the most trouble-free cinema systems available. I suspect people post DTS questions here a lot simply because *I* am here to answer them. Don't get me wrong, I love being available to you guys but sometimes it can be a double-edged sword.

The 2-drive player is a DTD-6 unit and the 3-drive player is the DTS-6D unit. The DTS-6AD is a cinema processor.

Many of the DTS problems people have stem from installation issues and once people know what to look out for, problems are solved. Informing you guys (and gals) is my job and I hope that it is of help to you.

Karen at DTS
khultgren@dtsonline.com

Posted by Karen Hultgren (Member # 395) on 08-05-2002, 01:24 PM:

Paul,

If you are having to reboot the player each time to get it to switch the CP to digital, I suspect that you are having timecode reading problems. Please send me an email and I'll send you some information on how to fix it.

Karen at DTS
khultgren@dtsonline.com

Posted by Karen Hultgren (Member # 395) on 08-05-2002, 01:53 PM:

When troubleshooting a DTS system, it's important to determine where the problem actually lies. If you are experiencing drop out problems, you need to check the reader and the drives.

Reader problems will be exhibited by blinking or nonesxistant TIMECODE light on the reader and player.

Drive problems are exhibited by the light on the drive itself becoming bright and steady. The drive light should wink at you when it is reading a disc. If that light comes on steady, it means the drive cannot read the disc.

It is very important to be as accurate as possible when describing problems so that we can get going in the right direction.

FOR ANTONIO - when it comes to the reader, adding the grounding strap should not dim the reader, it should brighten the LED *IF* your projector chassis is *not* earth grounded. If you need more information on this, please email me.

Karen at DTS
khultgren@dtsonline.com

Posted by Antonio Marcheselli (Member # 373) on 08-07-2002, 09:02 AM:

Paul,

I also believe that DTS is the most trouble-free digital system used.
However, most (all?) of the unit I saw has been badly installed.

To install a Dolby reader you NEED an oscilloscope. To install a DTS reader you need a screwdriver.

That's the difference. Someone thinks that install a DTS readers is just to use that screwdriver and put the readers on the projector.
It needs a bit of attention instead.

But when reader is correctly installed (I saw few, in Italy) DTS is almost trouble-free.

One of our player worked for 4 years without problems. After 4 years Dolby Digital LED has been replaced, DTS' led has been calibrated.

To change DD's LED our tech spent half a day, to calibrate the dts' LED I spent 10 minutes.

DTS just needs a bit of attention, it is still not "plug'n'play" compatibile

Bye

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Antonio Marcheselli
Florence, Italy