Film-Tech Forum ARCHIVE: DTS reader with bad LED

This is topic DTS reader with bad LED in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=010419

Posted by Joe Redifer (Member # 3) on 04-11-2010, 12:39 AM:

So we seem to have a DTS reader with a dying or at least really, really tired LED. I checked the voltage (without film) and I got less than half of a volt with the pot all the way up. What should I be getting? I hear it should be closer to 4v?

I assume there is no way to replace the LED in the field? The reader needs to go into the trash? How does one get this fixed and is it crazy expensive?

Posted by Phil Blake (Member # 2012) on 04-11-2010, 03:08 AM:

Joe think you are right 4volts is correct. probably cheaper to buy new one than fix old one.

Posted by John Wilson (Member # 269) on 04-11-2010, 05:36 AM:

They can indeed be fixed. Have had it done it several times.

Just send it to Spiro at Intech Pacific here in Sydney. He'll sort it out for you. [Big Grin]

Posted by Steve Guttag (Member # 268) on 04-11-2010, 07:21 AM:

DTS has an RX program for the readers. Yeah, it isn't cheap but it is cheaper than a new reader but it is like getting a new reader. They replace the worn parts (rollers), the LED and, most importantly, they replace the whole LED control circuit such that you won't need to fool with it again for a long-long time...there is no adjustment anymore, it auto levels.

Steve

Posted by Joe Redifer (Member # 3) on 04-11-2010, 11:42 AM:

Around $600 is the cost of this?

Posted by Steve Guttag (Member # 268) on 04-11-2010, 12:42 PM:

Probably closer to half of that.

Posted by Jim Cassedy (Member # 4115) on 04-11-2010, 01:46 PM:

Joe-
I had the same problem last December.

International Cinema/Magnetech in Florida will swap
out your DTS reader with a re-bulit/re-calibrated &
fully guaranteed DTS reader for only $200.00 when you
send them your old one.

I didn't want to wait for the DTS readers to make the round
trip, so you can also send them 400bux, which is what I did,
and they'll ship you one right away. As soon as they
get your old one they will credit your credit card or
Paypal account for the extra $200. They're really fast
& will issue your refund as soon as they get your old
DTS reader.

You can reach them at 305 573 7339

PS I hate to pick nits, but I don't think it's the LED voltage
you're meeasuring when you adjust the DTS reader to "4 Volts".

I beleive what you're actually measuring at the test points
is the output of the DTS "image sensor". You can confirm this
by blocking the light path while taking the voltage reading.
It will drop to "O" or close to it. If you were measuring the
actual voltage across the LED, it would remain constant no
matter if the light path was blocked or not.

Posted by Joe Redifer (Member # 3) on 04-11-2010, 03:01 PM:

Well, of course, since the test points are not even anywhere near the LED.

Posted by John Hawkinson (Member # 1135) on 04-11-2010, 03:40 PM:

Did you really measure it with no film? 0.5V is really low. We did have some success replacing the current-limiting resistor with a pot and jacking it up. After all, might as well get all the useful life out of it before we have DTS replace it.

Oh, also, the best way to calibrate DTS is with audio and your ears! (Think buzz track). Much easier than watching a DVM or a scope. We set up our rack so you can patch the DTS audio into the booth monitor speakers and listen to it. This is great for those shrunken DTS prints (not very many of them, dts isn't that old, but we've seen a few!). I'll post some pics and soforth when I get a round tuit.

--jhawk

Posted by Joe Redifer (Member # 3) on 04-11-2010, 04:11 PM:

At first I measured with film and then I took the whole thing over to the bench and measured without film. There really wasn't much of a difference, but it won't see most timecode. I was able to get it working on Crazy Heart, but some reels kept dropping out. But most prints it refuses to see any timecode.

Posted by Bruce Hansen (Member # 281) on 04-11-2010, 04:57 PM:

Look at the LED. Is it dim compaired to LEDs in other DTS readers? If not, then clean the LED and the lens. Make sure that the LED has not been "wacked" out of alignment. The solar cell could be bad, even the op amp could be bad. Try swaping the reader with another.

Posted by Joe Redifer (Member # 3) on 04-11-2010, 05:04 PM:

Wish I could, but this is our sole reader. The LED lights up but I have nothing to compare it to.

Posted by Gordon McLeod (Member # 33) on 04-11-2010, 07:23 PM:

For our own theatres ia have found a replacement LED that out performes the original but is only available in quantity and is not easy to replace

Posted by Edward Havens (Member # 4715) on 04-11-2010, 08:41 PM:

Steve, do you have more info on where one can go to learn more about this RX program? I have a couple DTS units with bad LEDs.

Thanks.

Posted by Mark Gulbrandsen (Member # 72) on 04-11-2010, 08:56 PM:

I rebuild them Joe... And my LED has longer life than theirs. I charge $100.00 flat to do it... well ok, for you a discount.... just $99.00 flat. Anyone charging $200.00 for this is raping you. I also guarantee the rebuilt reader for a year. In most cases the bearings and scanner drum are ok. If the scanner drum flanges are worn excessively then it has to go through an RA at DTS. I've done well over 50 of them... But no kidding... the new readers are really nice, track better, and never need adjustment.

Mark