Film-Tech Forum ARCHIVE: Aftermarket LED replacment part #'s Does any one know any??

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Posted by Jason Beard (Member # 4377) on 11-14-2008, 05:37 AM:

Hello all,

It seems like we have more and more L.E.D'S in the projection booth for sound [Frown]

some L.E.D'S seem to last forever, others seem to last 1 or 2 years...

The main reason I am starting this thread is I believe there are quit a few ppl. in here that knows enough about electronics & soldering to replace a L.E.D. I need to replace some L.E.D'S in a SDDS DFP-R2000 Reader & 1 L.E.D In a DTS time code reader (voltage is maxed out on both) But I dont want to buy Sony’s Overpriced L.E.D array assy. And I know that Sony does not make L.E.D'S, So there has ro be a 3rd party supplier for L.E.D'S , Not just Sony’s but all L.E.D'S… I am sure that I will have to replace a L.E.D in one of our many BACP reverse scan readers sometime.
I will say that I have never seen a L.E.D Like the one in the Sony reader, Wow it looks weired!!!! I have not taken apart a DTS time code reader or a BACP yet to see what those L.E.D'S look like..

So lets keep this thread all about part # of “after-market” L.E.D'S, Where to Find them, How to replace them, and any other technical info that might be useful for L.E.D Sound Equipment …. No bashing of equipment!!! Every where I read someone is complaining about Sony or someone Else’s equipment UGH maybe it all that theater can afford…

Now, I can not find any part #’s for L.E.D'S but I am gonna start out by what I have noticed on a sdds R2000 reader before replacing the L.E.D'S assy.

1. Removed the camera cover & the side accesses cover (the one above the cable connector 4 screws), grab a can of compressed air and start blowing, If there is No Dust or Emulsion in it, I wanna visit your booth!!!!!
2. Then after U blow most of that crap out, Remove the L.E.D assy. And use lens cloth or a lint free rag and clean the L.E.D. then use a Q-tip with lens cloth or a lint free rag over it and clean the 8 lenses where the L.E.D'S shine into (lenses for the Fiber optic cable) I would not use lens cleaner in case the Fiber optic is not sealed (does any one Know???)
3. Replace the the led assy. and the cover’s Make sure the red wire goes to the red plug and then clean the camera lenses on the sdds reader. I do this on all sdds readers before adjusting the L.E.D'S voltage… on some the voltage was fine, they were just dirty….
4. Even if the Voltage is maxed out Cleaning the L.E.D'S will Buy U some time till U can get some…
If u don’t know how to adjust the L.E.D'S Voltage go to Sony’s Website or on here there is a manual that tells u how to, I don’t remember if it is in tech bulletins or manuals… While I am here, why do u need a sope to adg. The voltage? Why can’t u use a Volt meter?

Later all,
Jason Beard

[ 11-14-2008, 09:52 AM: Message edited by: Jason Beard ]

Posted by Steve Guttag (Member # 268) on 11-14-2008, 08:07 AM:

Jason,

Serioiusly...just get the Sony current LED assembly (x2). Their price is 1/2 what they were when the system was current and the current versions (have a slight pinkish tinge) will last a LONG time and fade very slowly.

Steve

Posted by Marin Zorica (Member # 1716) on 11-14-2008, 10:47 AM:

You can try with some "ultra-bright" led's, well the question is how they will last because they are operated on high frequency so that is killing led's, but try...I did replace one reader by some cheap led's, they do work for a year now without fading.

Posted by Mark Gulbrandsen (Member # 72) on 11-14-2008, 01:10 PM:

Re=leding them yourself is extremely time consuming and there are many many other wear points on the penthouse that should also be checked during a refurbish. I've done alot of them and I won't even sell the bare LED's to anyone because its so difficult. Each individual LED has to be precision aligned and then glued in place once aligned so it doesn't move out of alignment. It takes me about 2+ hours to do them and I still do do them but only if one sends in the actual penthouse they mount on... I have found that doing it yourself is far superior to getting the Sony assemblies because each individual LED is position optomized for the penthouse it will live in... not on some general purpose factory alignment jig. I've also never had to re-led or even tweek the video level on any of the units I've rebuilt and some have been in for close to 5 years now!

Mark

Posted by Jason Beard (Member # 4377) on 11-14-2008, 02:40 PM:

Hello again All

OK U guys are kinda missing the point, I did bring up the SDDS, But there are so many more LED's, in audio, Like reverse scans, Dolby digital readers, DTS readers, Etc, This should not just be limited to Audio, there are alot of platters that need LED's also like the Christie Aw3's... I know there is a lot more to LEDs such as wavelength, Voltage, Current, Brightness, Etc. I know there are 3rd party suppliers that may have them such as allied electronics, Carlton Bates, Heck there is even a great electronics part store in Tulsa called Affiliated Electronics that has about every LED under the sun, I am Sure that any mid to large city has a simmilar Electronics part store. It would be nice to have replacement part numbers or equivalents in case U get into a bind and need to get something up & running A.S.A.P even if temporary until U can get the correct LED If No 3rd part led is avaliable...

Later,
Jason

Posted by Mark Gulbrandsen (Member # 72) on 11-14-2008, 05:46 PM:

Reverse scan LED's have to come from USL or Dolby... They are custom made LED arrays.

Mark

Posted by Marin Zorica (Member # 1716) on 11-14-2008, 05:53 PM:

quote:
Re=leding them yourself is extremely time consuming and there are many many other wear points on the penthouse that should also be checked during a refurbish. I've done alot of them and I won't even sell the bare LED's to anyone because its so difficult. Each individual LED has to be precision aligned and then glued in place once aligned so it doesn't move out of alignment. It takes me about 2 hours to do them and I still do do them but only if one sends in the actual penthouse they mount on...

First time I did replaced complete reader led's (two boards, 12 led each) for about 45 min and align them, you don't have anything special there to align, mostly they fit good as original was, just check by moving each led do you need to align it, and after that just set level to nominal value. Setting of level is explained in sony's technical bulletin, you may find that on SDDS web.

List some catalogue, find red led's which can produce more light, and use them....you will see it will work, that led inside are nothing more special than this one, specially that was 12 years and today are many better and cheaper led's.

Also, you may check if possible in data sheet what is maximum respond time of led, because this one are driven by higher frequency, don't know which, but you can refer to that in manual.

quote: Mark Gulbrandsen
Reverse scan LED's have to come from USL or Dolby... They are custom made LED arrays.

Good point....I beet I did saw one time on web led so similar to this one's, but can't recall where it was.

Posted by Christos Mitsakis (Member # 143) on 11-15-2008, 03:21 AM:

How about this?
Led replacement on ebay

C.

Posted by Monte L Fullmer (Member # 2797) on 11-15-2008, 03:43 AM:

Let's take a side step on LED topic. I want to ask a question on an idea that I'm wonder if this could work or not:

The lot of us have dual LED readers - optical and digital. Most of our equipment are using the digital side of this spectrum. Thus, the lowly optical reader hardly gets used.

Now, there is that practice of wiring the LED transformer across the motor run taps on the TB board of many consoles so the LED's are off when machine is at rest.

Now, can we go one step farther on this by somehow having the processor control which LED to switch on depending on which format is used?

This would save tonnage of LED usage and extend LED life, esp the optical, 10 fold if this can be all possible.

-Monte

Posted by Marin Zorica (Member # 1716) on 11-15-2008, 05:21 AM:

quote: Monte L Fullmer
Now, can we go one step farther on this by somehow having the processor control which LED to switch on depending on which format is used?

Let's say for changeover situation enough would be to get led's controlled by dowser or motor start, but switching led's by format would be bad, because in moment digital fall of analog led must be switched on, and on same time processor would fall to analog so that will probably occur some pops in sound, also if we play in analog, how the processor would know is there a digital if led is off [Big Grin]

Posted by Mark Gulbrandsen (Member # 72) on 11-15-2008, 08:40 AM:

Marin...

It helps to use a scope and look at the video waveform when adjusting the LED's and of course the most critical ones are the center row. The outer rows are jut for shading and evening out the waveform. In some cases you can almost live without them all together.

Mark

Posted by Marin Zorica (Member # 1716) on 11-15-2008, 09:40 AM:

Mark, normally for aligning i was think using a scope, you can't set that without a scope.

Posted by Sam D. Chavez (Member # 1841) on 11-15-2008, 10:58 AM:

The LED on the link may or not be a Dolby 32075, the only genuine part for use for reading analog and to a slightly lesser extent, sound tracks.

The price is about what I charge my good customers as the part costs me $50 in large quantity.

The best costs more.

Posted by Marin Zorica (Member # 1716) on 11-15-2008, 01:34 PM:

Sam, if is not secret, what led's do you use in you're readers?

Posted by Tony Bandiera Jr (Member # 2365) on 11-15-2008, 02:37 PM:

Oh for cryin out loud..people need to wake up to some simple economics and quit bitching about "How expensive" projection parts are.

Some simple math for y'all:

Let's say a replacement LED for your reader costs $100.00

And worst-case life is that it lasts for one year....

$100.00 divided by 365 days = $00.2739726 or 27.4 CENTS PER DAY!!

For two year life of course the actual cost is half that, or $00.1369 or about 13.7 CENTS A DAY

By screwing around and trying to find an untested, unknown quality replacement LED, you'll lose a hell of a lot more money in downtime and refunds.

This same rule of economics applies to the foolish attempt to save a few bucks with no-name, imported Xenon lamps.

Posted by Marin Zorica (Member # 1716) on 11-15-2008, 03:32 PM:

quote: Tony Bandiera Jr
This same rule of economics applies to the foolish attempt to save a few bucks with no-name, imported Xenon lamps.

USHIO and OSRAM are also imported? [Eek!]

Posted by Monte L Fullmer (Member # 2797) on 11-15-2008, 03:35 PM:

He's talking about "charlie chan", five buck special import bulbs.(I could also throw LTI bulbs in this mix as well...)

We all know that Osram and Christies (Ushios) have proven themselves in worthiness..

Posted by Marin Zorica (Member # 1716) on 11-15-2008, 03:48 PM:

I know....just kidding [Big Grin]

Posted by Sam D. Chavez (Member # 1841) on 11-15-2008, 04:59 PM:

Marin, are you kidding again?

I use the Dolby LED's of course, the part I quoted before. I am a licensed manufacturer of Dolby analog and digital readers and using Dolby parts in Dolby readers is part of the deal.

I sell to dealers all over the world. I don't quote prices on Film-Tech and I sell LEDS in quantity of 20 or more as it does not make sense to ship less than this due to high shipping cost except in the USA.

Posted by Tony Bandiera Jr (Member # 2365) on 11-15-2008, 11:31 PM:

Thanks Monte for clarifying my remark on the xenon bulbs. [Smile]

Of course, technically both Osram (Germany) and Christie/Ushio (Japan) bulbs are imported as well.

But both brands as Monte stated have proven themselves to be quite reliable.

The adage "You get what you pay for" holds especially true in our industry, with the disadvantage of a lot of our equipment isn't as mass-produced (quantity-wise) as most other lamps/parts.

My rant was intended to point out the fact that a lot of folks, in management and other areas, don't think carefully about the REAL cost of "bargain" or "cheaper" parts and equipment. A memeber of this forum is suffering through this very issue, as someone in his employer's chain of command thought that projectors and platters made in a certain notorious country would be a great way to save some money. I'm willing to bet that if the REAL costs of all the repairs and lost shows is added up, it would have been CHEAPER to install a reputable brand of equipment, even the less-than-perfect stuff from Ballenswine. [Smile]

Once customers have repeated bad experiences at your theatre, not only will they not come back, but you can bet they won't tell thier friends and coworkers anything positive about your theatre. [Smile]

Posted by Jason Beard (Member # 4377) on 11-15-2008, 11:44 PM:

Hello all
Christos Mitsakis thanks!!!!

That is what I was talking about, I will have more info on that LED array very soon!!!!

Monte Fullmer,
That is a great idea, I have built many cables for DTS units, I think there is a pin out for DTS that Drops the - output as soon as it loses the time code But it still plays audio (there is like a 5 to 10 sec time frame from when DTS looses time code but it still plays Audio then it drops the signal to change The processor to Analog) If so Using a relay it would be simple to Tie this to the Reverse scan Power, it would power up the reverse scan before the DTS audio Drops (hence no audio pop)... I will Also call DTS to see if it is possible to Shut off the DTS reader Led without causing a error code until you start the Projector.. I will post some diagrams soon on how to shut down the reverse scan until you start the projector, that is easy!!! I bet that there is also connection in a SDDS that would also have a signal that would "output" to power up the Reverse scan before the sdds drops to analog.

I also just noticed that in the setup for the sdds that there is a check box to use the sdds back up track or to revert to Analog sound, I am going to change that setting tonight, I saw it Yesterday morning at 3 am but did not fell like Testing it (I needed to get some zzz's)...

Sam Chavez, Cool, U have the replacement Led assy for a little over $50 I have not had to mess with any of those yet, I figured that they would cost over $100 from Dolby, bacp., Ect. That is really not that bad at all... I would buy one If I needed it for around $50 just to get rid of the headache of knowing it should work right for the long haul.

Now with that being said, I am familiar with that type of led array, I Also Know that that they can be bought for $10 to $25 But I want to make sure that the specs are the same... Like I said earlier. I iwll have some more info soon on them... Also They sell that type of array at my local electronics supply store, if I had a screen down and needed to get it up, I could get it up only missing 1 or 2 show as opposed to a min 2 day down time by ordering (before all U say something, what I mean is if the screen goes dark at lets say the 7 P.M. shows, u cant order till the next morning, they overnight, U get it around 3 pm the next day then U have ti install it and re do a A chain, U missed 2 days...)

Thanks all, Great post!!!
Jason

Posted by Monte L Fullmer (Member # 2797) on 11-15-2008, 11:45 PM:

quote: Tony Bandiera Jr
Once customers have repeated bad experiences at your theatre, not only will they not come back, but you can bet they won't tell thier friends and coworkers anything positive about your theatre.

Agree on this one what Tony has mentioned here and want to comment on this even though this ALMOST drifts off-topic, thus forgive me on this one moment:

A friend of mine, who's father was in a retail business in a large "big box" chain, told me what his father told him about the "Rules of Seven":

1-If you can make SEVEN people satisfied in your business practices, at least ONE of them will spread the news around on how your business is and how you'll be treated.

2- BUT, if you just piss off just ONE person by not making sure that they're satisfied, or even failed in your business practices, that ONE person will definitely tell SEVEN others.

..and how many times have we've seen this attending some cinemas - large and/or small?

I ran out of fingers and toes trying to count. And you wonder why this form of business operation is being practiced.

quote:
I will post some diagrams soon on how to shut down the reverse scan until you start the projector, that is easy!!!

Great! Please do post diagrams so the lot of us can start saving on LED usage...and you're welcome. Glad I thought of that.

-Monte

Posted by Tony Bandiera Jr (Member # 2365) on 11-15-2008, 11:55 PM:

quote: Jason Beard
....I Also Know that that they can be bought for $10 to $25 But I want to make sure that the specs are the same... Like I said earlier. I iwll have some more info soon on them... Also They sell that type of array at my local electronics supply store, if I had a screen down and needed to get it up, I could get it up only missing 1 or 2 show as opposed to a min 2 day down time by ordering (before all U say something, what I mean is if the screen goes dark at lets say the 7 P.M. shows, u cant order till the next morning, they overnight, U get it around 3 pm the next day then U have ti install it and re do a A chain, U missed 2 days...)

Jason, while I can agree with the idea of minimal downtime, I repeat what I said in my first post on this thread as to the uncertainty of using a cheap part, even in an emergency...as now you'll have to replace that SAME PART TWICE, if you're wanting to ensure maximum life and relaibility. A $10-15 dollar part WILL NOT have the same specs in any event.

If you're concerned about minimum downtime, (and that's very admirable) how about ordering the RIGHT PART in advance? [Roll Eyes]

What a concept. Again, the cost with all the things I've already mentioned factored in works out to pennies a day, cheap insurance against dissatisfied customers.

Monte, Brilliant post, that "Rule of Seven" is great. [thumbsup]

Posted by Jason Beard (Member # 4377) on 11-16-2008, 12:18 AM:

Hello again all,

Ok I feel like a IDIOT!!!

Sam,

I was just reading in the dead beat forum (noting bad at all toward Sam or BACP) & found out U work at or own BACP Cool!!! We have 13 of your reverse scans Great product!!! Pls. Dont take offense to me trying to find lower priced led arrays... I do have 1 issue with the BACP reverse scans with the Higher frequency response, that I will post in the correct area (if I can find one)... PLEASE DO NOT GIVE ME ADVIDCE ON THIS ISSUE HERE, I want to keep this thread to LED Info!!!!

Tony, I do agree 100% with what U said about the cost Per day of the LED. I am mainly trying to get to the point of finding local parts & maybe trying to find Permanent parts that don’t cost $100 for something that on the component level cost $10 to $25, Why pay 300% markup if U don’t have to..... Also if no local parts are avl. and if u did have a screen go dark to no or really bad sound & if U had to order a LED for a dolby, sony, DTS, Christie, Ect. equipment First U have to contact your supplier, they have to find the correct part #, and in our case, Our suppler is 2 hrs behind us in time so we cant call them till 10 am, then they call the equipment manufacturer, Then they have to try to pull it and get it shipped overnight, so U are down even more time... It is all delays while u have a dark screen making U NO MONEY.... It is allot less work and easier if u can just order the part directly Locally or from someone like Allied Electronics, Carlton Bates, Ect.

Also, If I could buy a replacement part (not just LED's) that retails for $300 for $10 to $50 that part would be on my parts shelf For when I needed it!!!!!

To all:
I am happy to see so many post in here!!! But after reading the deadbeat forum I want to say this again. Please keep this thread to the topic of LED's!!!! In the Dead beat forum I noticed 5 or 6 ppl. or companies that were actually reported for having bad business practices in 11 pages, It seems it is easy in film tech to get off the topic [Smile]

Thanks All,
Jason

Posted by Mark Gulbrandsen (Member # 72) on 11-16-2008, 10:54 AM:

quote: Tony Bandiera Jr
This same rule of economics applies to the foolish attempt to save a few bucks with no-name, imported Xenon lamps.

Tony, Don't forget that all good xenons are also imported.... You use LTI? I don't think you do and I certainly hope not! 98% of the lamps we selll are Christie. Your math shows they are by a very large margin the cheapest lamps to run on a per hour math basis.

Mark

Posted by Sam D. Chavez (Member # 1841) on 11-16-2008, 11:01 AM:

Various points here.

The readers can be powered up and down, no problem, but depending on how it's is done, the LED will issue a giant pop into the sound, maybe enough to break a marginal speaker. The reason is the LED comes up to full brightness in an instant, unlike an exciter lamp that comes up slowly. I'm sure some of you have noticed LED taillights on cars and how fast they come on and off, compared to the original bulbs used for this.

There may be other similar LED arrays to the Dolby LED, but I have not seen them. They definitely are not off the shelf as this is a specialty item made specifically for this application.

As to price, the figure I mentioned is the price I pay for 100's at one time, so I'm not selling at this price.

Lastly, to Jason's point about HF response, get in touch with me, I don't know the issue to which you refer.

Posted by Mark Gulbrandsen (Member # 72) on 11-16-2008, 12:12 PM:

Sam,

I seem to remember that you do have a cure that you sent us at CLACO that works for that instant on thingy... an R/C delay of some sort as I remember. So its a problem that can be delt with by making the LED come up sloooowly with the simple addition of a very simple R/C network...

Mark

Posted by Steve Guttag (Member # 268) on 11-16-2008, 12:14 PM:

Okay...lets review some points of fact and fiction here...

Catastrophic LED failure in the visible LED are near zero. That is, how many of you have had an LED just up and quit? Anyone? Anyone? I've had some of the early IR LEDs give me "snake eyes" where the middle portion died. I have had a partial failure on the visible reds but nothing statistically significant.

Next...which service company/dealer does not STOCK these LEDs the same way we used (and to some degree still) stock exciter lamps? Since the Dolby (USL) LED works in virtually ALL basement type LED based readers, even a single spare LED can be your emergency spare for all of your basement readers. Haven any digital readers? In a pinch, that LED can be moved to analog use to ensure 100% continuous sound reproduction...as such, any argument of needing a cheaper LED to justify stocking at least one is just plain bullshit.

Sam made the mistake of discussing his prices here and I suggest nixing that....one should discuss List prices on a public forum...normally "dealer" prices come with a "Confidential" agreement in the form of a non-disclosure.

The LIST price for the Dolby LED is $80.00...that is what is published....so you figure what an OEM pays for it, what a dealer pays for it and then what you, the end user pays for it...NOBODY is getting rich here on selling raw LEDs.

When people look at cinema equipment (including parts) and their prices, one needs to also factor in quantity...we are a TINY industry...selling something in the 100s is consider good, in the 1000s GREAT and in the 10,000s absolutely incredible.

So if a manufacturer sells a gear, lets say for $50. If it were 100% profit and they sold a whopping 500 of them that year...that would be a $25,000 part in gross profit. So who can live on that? Then look at the NET price and you should realize no one part is getting anybody rich in this industry. One can eek out a decent living handling many parts but again nothing that approaches "rich." If theatres had to live on the profit margins that equipment dealers live on, they would ALL be out of business. Most any of the equipment manufactures that have had staying power have also had business outside of this industry.

So an LED for $80 or less, get over it...it is cheap on the cost/hour basis. Even cheaper on the cost/dollar generated.

Why would one pay $80 when a $10/$15 version is available...well most wouldn't and probably shouldn't...if it existed. In the case of the Dolby LED...it is purpose built (package that has the array of LEDs, wavelength, illumination area...etc) and more than likely, there isn't a suitable replacement.

Mind you...there are TONs of cases of people here recommending aftermarket parts that are the exact same but for less money using traditional supply sources. As an example...the venerable Potts/Strong platter. The microswitches, motors, motor parts...etc can all be sourced by traditional sources...You are getting the exact same part (or even better, in some cases) and paying less while doing it. In the case of the Dolby LED...that is not the case however.

Steve

[ 11-26-2008, 09:21 PM: Message edited by: Steve Guttag ]

Posted by Tim Reed (Member # 137) on 11-16-2008, 01:48 PM:

quote:
if no local parts are avl. and if u did have a screen go dark to no or really bad sound & if U had to order a LED for a dolby, sony, DTS, Christie, Ect. equipment First U have to contact your supplier, they have to find the correct part #

Oh, for heaven's sake, things cost what they cost. If buying a spare part is going to break the bank, that's probably indicative of a greater problem. [Wink]

Steve is right; LED arrays don't normally just drop dead, so it's probably unnecessary to keep a spare in the booth. However, here's the proper way of looking at this in regards to critical parts: is the loss of revenue and goodwill of having a dark screen worth the few bucks saved not stocking it?

Posted by Jeremy Weigel (Member # 4208) on 11-16-2008, 02:34 PM:

quote: Steve Guttag
That is, how many of you have had an LED just up and quit? Anyone? Anyone?

Yep. Happened to me just a few weeks ago with a Component Engineering ASR-40 reader.

Posted by Mark Gulbrandsen (Member # 72) on 11-16-2008, 03:16 PM:

Yep! It is still somewhat common for segments to go out in Digital readers of all makes. Readers that have slower speed lenses are gonig to go throgh more leds than the newer designed stuff will. Analog LED's.... I replaced just three or four in the last year that were quite old... I actually see more failures of Kelmar analog power supplies than I do anyones analog LED's these days.

Generally we always have at least 25 LED's on the shelf and a half dozen in each service van... we do cover ALOT of screens. Also, failure of one LED at a site in which all the gear went in at once usually means failure of the others is not that far behind... they all now seem to fail pretty close together.

Mark

Posted by Tony Bandiera Jr (Member # 2365) on 11-16-2008, 04:11 PM:

quote: Mark Gulbrandsen
Tony, Don't forget that all good xenons are also imported....

I already mentioned that in a previous post... [Big Grin]

quote: Moi
Of course, technically both Osram (Germany) and Christie/Ushio (Japan) bulbs are imported as well.

Jason, you're STILL missing a key point:

quote: Jason Beard
....Also if no local parts are avl. and if u did have a screen go dark to no or really bad sound & if U had to order a LED for a dolby, sony, DTS, Christie, Ect. equipment First U have to contact your supplier, they have to find the correct part #, and in our case, Our suppler is 2 hrs behind us in time so we cant call them till 10 am, then they call the equipment manufacturer, Then they have to try to pull it and get it shipped overnight, so U are down even more time... It is all delays while u have a dark screen making U NO MONEY.... It is allot less work and easier if u can just order the part directly Locally or from someone like Allied Electronics, Carlton Bates, Ect. ....

To clarify from your response above:

"If you had to order... " That's why you order at least one part IN ADVANCE.

"Dolby, Sony, DTS Christie etc...."

AFAIK, Dolby, Christie, BACP, Kelmar and Comp Eng. all use the same LED array. DTS and Sony of course have unique parts. As for DTS, it's cheaper to have a spare reader assy on hand,, and quicker to change out.

"Our suppler is 2 hrs behind us in time so we cant call them till 10 am, then they call the equipment manufacturer, Then they have to try to pull it and get it shipped overnight, so U are down even more time... It is all delays while u have a dark screen making U NO MONEY.... "

Again, that is why you order the spare in advance. Thus the reason it's called a spare part. [Roll Eyes]

"It is allot less work and easier if u can just order the part directly Locally or from someone like Allied Electronics, Carlton Bates, Ect. ..."

A lot less work? The time you've spent on this thread is a hell of a lot more than the time you would have spent calling your supplier and ordering the right part in the first place. Sheesh.

While I can respect someone trying to keep their booth running and trying to do so without spending gobs of money, I have little patience for anyone who won't listen to the advice that just about everyone in this thread has given, which is to quit horsing around, order the right part from the OEM or some of the fine dealers here (Why not contact Sam or Mark by PM and get a price quote from them?) and end this nonsense?

Another good quote to keep in mind:

"There's never enough time or money to do it right the first time, but there's always enough time and money to do it again when someone screws it up."

Edited to add: I'm sorry in advance if some of the comments come off as a bit harsh, and I am not trying to attack anyone personally. I just want to make sure the message is finally beginning to sink in. [Wink]

Posted by Sam D. Chavez (Member # 1841) on 11-16-2008, 05:44 PM:

I agree totally with what Steve posted, but this topic has gotten beyond tedious.

Posted by Mark Gulbrandsen (Member # 72) on 11-16-2008, 05:46 PM:

quote: Tony Bandiera Jr was the last to post
Carlton Bates

Wasn't he that States Attorney guy on Perry Mason???

Posted by Eric Robinson (Member # 2966) on 11-17-2008, 09:44 AM:

Regarding the added complexities of switching LED's on and off when need/not needed. Just for sanity sake, why not keep it simple. I know I would be somewhat annoyed if I had to spend my time reverse engineering someones fancy LED switching scheme if I happened to be the unlucky chap called to the theatre. I'm sure I would take one look at it, say to myself "what the hell is this?", and then prepare for a long journey of reverse engineering to solve possibly a simple problem.

Posted by Sam D. Chavez (Member # 1841) on 11-17-2008, 06:34 PM:

Besides the pop when the LED comes on and off, I've seen some examples of very poor wiring on the LED when some one installed a switch. Bad wiring on a tiny low current wire and of course, no sound at all when the LED fails to come on for whatever reason.

Posted by Tony Bandiera Jr (Member # 2365) on 11-17-2008, 08:46 PM:

quote: Mark Gulbrandsen
quote: Tony Bandiera Jr was the last to post
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Carlton Bates
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Wasn't he that States Attorney guy on Perry Mason???

Nope, but I think he's related to Master Bates. [Big Grin]

Sam:

I too have encountered that same problem, when someone wires in a switch or worse, cheapest relay they can find, to control the LED.

Posted by Ken Lackner (Member # 1002) on 11-17-2008, 09:35 PM:

Slightly off topic. I would never attempt to devise a scheme whereby the LED is only on when the processor switches to that format. That's just crazy. But most every theater I've operated or serviced has been set up so the outlet that the LED power supply is plugged into is switched with the projector motor. (No crazy wiring or relays between the power supply and LED.) The LED is on any time the motor is running. This goes for analog of any type, and Dolby Cat. 701. (I wish it could be done with the Cat. 702 and the BACP penthouse.) What is the general opinion of this method versus leaving the LED on whenever your equipment is powered up?

Posted by Steve Guttag (Member # 268) on 11-18-2008, 06:57 AM:

We have some non-theatrical installations where the CP650/DA20 is never turned off. As such, the LED in the digital reader would have a really short life. Also, these types of venues may not run a predominate amount of film...further leading to a short useful life.

I have modified the BACP (Rather easily) to turn the LED off when not in use. If you can work with Molex "KK" type connectors, the method of modification is pretty self-apparent. I recommend using the Molex-KK because no wires need be cut and the unit can be "unmodified" in seconds if the unit needs to go back for repairs. I remember in one venue, we merely mounted a switch in an unused mounting hole (Say one of the mounting holes for a Cinemeccanica)...you merely turn the light off when not in use...this, of course, turns on the RED led to signify that the LED level is not bright enough but I don't mind that one fading a tad!

I want to say that current Cat 702s have a pair of terminals that, if shorted or the use of a resistor to connect will kill the LED...but would check with Dolby on that one.

By and large, 95% of our readers are of the basement type and they all are switched with the motor circuit.

Steve

Posted by Scott Norwood (Member # 30) on 11-18-2008, 08:41 AM:

quote: Steve Guttag

By and large, 95% of our readers are of the basement type and they all
are switched with the motor circuit.

This doesn't cause SRD dropouts at changeovers? (I'm assuming that it does not, otherwise you wouldn't have installed them this way, but I've never seen an SRD reader wired this way.)

Posted by Steve Guttag (Member # 268) on 11-18-2008, 09:28 AM:

Scott,

Re-read you post...of course it would not cause drop outs at changeover...the motor comes on 7-seconds prior to changeover. The projector isn't up to speed for 3-5 seconds (depending on brand, ramp up...etc) so anything before that time is jibberish and un readable. In a changeover, it is only the data that is read just prior to changeover (determined by offset...in the case of basement readers...about 20-26 perfs or 5-6 frames).

What WOULD cause drop outs would be turning on the LED at changeover and even that might not cause a problem due to "splice cache." The information around a reel change is backed up to ensure a smooth changeover.

Steve

Posted by Monte L Fullmer (Member # 2797) on 11-18-2008, 05:55 PM:

Now, here's a variation to what I brought up here on this LED switching issue that I thought about:

What about keeping the LED on, but us a A/B switching device where one leg of the switch has a resistor that would drop the voltage to the LED in half when not in use. Course, this would all installed after the PS.

At least, where not facing the sudden on issue as what Sam brought up with the possibility of damaging drivers and still the life of the optical LED's would be extended drastically.

Posted by Sam D. Chavez (Member # 1841) on 11-18-2008, 06:29 PM:

I don't think this will work well as an LED is a current not a voltage device, that is to say, the voltage across the LED stays more or less the same, regardless of the current. The pop would still be a problem as it goes from one brightness level to another in an instant, not at all like a light bulb.

Posted by Tony Bandiera Jr (Member # 2365) on 11-18-2008, 06:32 PM:

Monte, not a bad idea in principle, (edited to add: Sam's post went in as I was typing this one) but again, for what feels like the hundreth time, I state that the COST OF THE LED DOES NOT JUSTIFY the time, expense and added system complexity (and adding another potential breakdown point) vs. the "savings" in LED life.

Sam has the best quote of this thread: (Bold added by me.)

quote: Sam Chavez
I agree totally with what Steve posted, but this topic has gotten beyond tedious.

Posted by Monte L Fullmer (Member # 2797) on 11-19-2008, 01:46 AM:

True, I can change out an LED in less than a half hour in a CE holder. Not that all difficult to do esp. if you got all the test equipment to realign everything when done.

So, I'm gonna be quiet on this one - let someone else chime in with their ideas and comments.

-Monte

Posted by Eric Robinson (Member # 2966) on 11-19-2008, 09:36 AM:

I have looked around for data about LED life regarding leaving it on all the time and switching it on and off. I haven't come across any data which suggests that turning an LED on and off repeatedly will make its life any shorter. The data I did see though is that over a period of time, the light output of the LED will decay. Additionally there was an emphasis in the data to properly heat sink LEDs because the heat factor at the LEDs junction is a primary cause of performance degradation. From all of this data I would conclude the following:

1) The less time the LED is on, the less time it is subject to light output decay.
2) Use heat sink compound and heat sinks properly.

So, as far as turning the LED on and off, for the sake of keeping it simple, it sounds like the motor circuit is a great choice.

As for the heat sink, I would have to put my trust in the hands of the engineers who designed it. [sleep]

There must have been some studies done by the people who came up with this whole design.

Which leads me to a question: Does anyone know where I can get pictures and information about the Dolby LED array? I remember once seeing a closeup picture of the tiny gold wires which were soldered to the individual LEDs.

Posted by Tony Bandiera Jr (Member # 2365) on 11-19-2008, 02:18 PM:

[sleep]

Posted by Todd Shelskt (Member # 4684) on 11-22-2008, 09:45 AM:

Hi, we have the Kelmar Basement Readers with Dolby Digital. We bought a couple of LEDs -- at $100 a pop -- but I've never replaced them before. Can someone quickly go over the steps with me, or point me to some on-line instructions? Thanks.

Posted by Mark Gulbrandsen (Member # 72) on 11-22-2008, 09:52 AM:

You paid Waaaaaaay too much for those!!!

You need to perform a complete A chain alignment after replacing them. While doing the A chain you should need to turn down the LED voltage in the Kelmar power supply and turn up the preamp gain to get the maximum life span from them. For instructions on doing this take a look on the Manuals Page... look at the CP-65 manual "A- Chain" alignment instructions... it's extremely well written.

Mark

Posted by Ken Lackner (Member # 1002) on 11-22-2008, 12:28 PM:

Unless you have proper training (and authorization), test films, and test equipment, which means a dual-trace oscilloscope and a real-time spectrum analyzer (RTA), this task should be left to a qualified service engineer.

Posted by Tony Bandiera Jr (Member # 2365) on 11-23-2008, 12:08 AM:

[sleep]

Posted by Ken Lackner (Member # 1002) on 11-23-2008, 12:29 AM:

The original topic of this thread was starting to get really silly, but we have drifted from that and now other people are asking some legitimate questions. What's the problem here??

Posted by Steve Guttag (Member # 268) on 11-23-2008, 09:29 AM:

It all depends...if people are bitching about the cost of the LEDs ($80.00 list from Dolby), then Tony is right [sleep]

The cost/hour is insignificant.

If we are talking about extending LED life by switching them on/off, then Tony would be quite out of line with his [sleep]

By extending the life, using a motor circuit, it means that the LEDs will reduce their fade enough to ensure that it is likely that thing will remain good between PM visits. IF they were left on all of the time, they typically do not accomplish this. The cost of the LED then pales in comparison to extra service visits just to change/align them.

In fact, some of my special venue theatres use their systems infrequent enough that LED fade would be the bulk of what they have as they may only use their film projectors 4-10 times/year (Though their CP650 or like processor may be used daily).

Switching the LEDs with the motor circuit is easy and self-explanatory. One would be foolish NOT to do it.

Steve

[ 11-26-2008, 09:22 PM: Message edited by: Steve Guttag ]

Posted by Mark Gulbrandsen (Member # 72) on 11-23-2008, 10:04 AM:

quote: Ken Lackner
Unless you have proper training (and authorization)

I don't get the (and authorization) part.....

Mark

Posted by Louis Bornwasser (Member # 3063) on 11-23-2008, 10:27 AM:

Certain circuits require a certification/license to do certain work. Keeps the untrained from going in over their heads. Louis

Posted by Ken Lackner (Member # 1002) on 11-23-2008, 11:35 AM:

quote:
It all depends...if people are bitching about the cost of the LEDs ($75.00 list from Dolby), then Tony is right [sleep] The cost/hour is insignificant.

If we are talking about extending LED life by switching them on/off, then Tony would be quite out of line with his [sleep]

Exactly. What we (well, not me) were talking about originally was getting rather ridiculous, but I think this has turned out to be a very informative thread.

quote: Mark Gulbrandsen
I don't get the (and authorization) part.....

I imagine most owners, whether they are individuals or circuits, would not want a projectionist performing tasks that should be left to a technician. It was pretty much a disclaimer from me, in effect saying that unless you know what you are doing AND are authorized to do it by YOUR employer, do not do it.

Posted by Ken Lackner (Member # 1002) on 11-23-2008, 11:36 AM:

quote:
It all depends...if people are bitching about the cost of the LEDs ($75.00 list from Dolby), then Tony is right [sleep] The cost/hour is insignificant.

If we are talking about extending LED life by switching them on/off, then Tony would be quite out of line with his [sleep]

Exactly. What we (well, not me) were talking about originally was getting rather ridiculous, but I think this has turned out to be a very informative thread.

quote: Mark Gulbrandsen
I don't get the (and authorization) part.....

Posted by Tony Bandiera Jr (Member # 2365) on 11-24-2008, 01:54 AM:

quote: Ken Lackner
EDIT: Um. Wow. Don't know how that happened. (Referring to the double post. Does a moderator care to delete one?)

Happens to me on another forum when using IE for some strange reason...

As for the [sleep]

I was trying to be somewhat funny, not intending disrespect for the new direction of this thread, although I do believe we've discussed the whole switching the LED thing on another thread a while back. [Smile]

As for switching the LED: In special venues that don't always run film or do run a lot of video, and the LED supply happens to be in the sound rack (and thus powered on when the rack is) sure, I agree that shutting it off when not in use is going to save a good amount of LED life. In fact, the screening rooms I build are set up so that the LED's don't come on until the film mode is selected in the booth.

However, in an average cinema where intermissions may be as little as 1/2 hour, with 5 shows daily that's only 1.5 hours of extra 'on" time if not switched with the motor. If the intermissions are longer of course that time increases.

Again, I still don't see (and in most of the installs I've run into so far) the need to switch the LED to gain that much extra lifetime.

You'd get better overall LED life by making sure when it's installed that the physical alignment is done properly to maximize the intensity and uniformity, then reduce the LED current as much as possible, while tweaking the pre-amp gain up (being careful not to go too far and have added noise.)

And Sam and/or Mark , please correct me if I'm wrong, but wouldn't switching the LED off and on tend to stress it more than just leaving it on?

In any event, it's always good to do what works best for your customers, no matter what differences in opinions are expressed here.

Posted by Louis Bornwasser (Member # 3063) on 11-24-2008, 05:41 AM:

Tony; you'd be surprise how many "intermission" hours a cinema has nowdays. (I put a lamphouse meter in the bottom of the sound rack and compared the hours over 2 years to the one in the lamphouse: TWICE as many.) Louis

Posted by Steve Guttag (Member # 268) on 11-24-2008, 07:00 AM:

Tony,

Do your own experiment...Have some LEDs (particularly the ones that work with the Digital track) on all the time...some switched with the motor. You'd be amazed at the life difference...pretty substantial are my findings.

Originally, we DID wire all of the LEDs on all of the time...and then switched due to the life span the LEDs were giving us...again, primarily on the digital side as they need more current for good level.

Steve

Posted by John Hawkinson (Member # 1135) on 11-24-2008, 10:06 AM:

When you guys switch the LEDs, do you switch the DC to the LED, or do you switch the 120VAC to the supply? Solid-state or mechanical?
Do you also switch DTS LEDs?

--jhawk

Posted by Tristan Lane (Member # 1169) on 11-24-2008, 11:17 AM:

In almost all cases, I would use the motor circuit to feed the LED power supply.

Posted by Steve Guttag (Member # 268) on 11-24-2008, 01:36 PM:

For Component Engineering units, most are switched via AC...it is just too easy to wire the IEC cord to the motor circuit. For SOME 40-series CE units, we use the provided terminals on the supply to switch the LED as it has a "soft-start" circuit.

For Kinoton, we use the internally provided terminals for turning the LEDs on/off.

Steve

Posted by Todd Shelskt (Member # 4684) on 11-28-2008, 05:50 PM:

Hey, everybody, thanks for all of your responses! Our theater may be hiring an independent technician one of these days. Maybe I'll end up looking over his shoulder as he changes the LEDs.