Film-Tech Forum ARCHIVE: DTS reader light blinks irregularly

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Posted by Richard May (Member # 2627) on 07-12-2005, 07:12 PM:

Can't seem to find this topic covered anywhere. The timecode seems to drop out for less than a second at a time. This does not happen often. The green light on the reader is bright and steady. Every 30-40 seconds or so, the reader light will blink off for half a second. The operators tell me that it keeps defaulting back and forth from digital to optical. Everytime I am there, it does not default. Either way, I do see the green light on the reader flashing every so often. There is no pattern to it to connect it with the platter or any other piece of equipment. They have Christie platters. I tried with the spring installed and removed from the center brain roller. All the rollers are running smoothly and aligned perfectly. It's weird because it will run for minutes at a time without flashing. All upgraded boards and chips installed in DTS6.

[ 07-12-2005, 10:32 PM: Message edited by: Adam Martin ]

Posted by Brad Miller (Member # 2) on 07-12-2005, 07:22 PM:

It's not dropping to analog, and yes that is normal.

Posted by Michael Schaffer (Member # 1204) on 07-12-2005, 11:55 PM:

Timecode has to be lost for a continuous 4 seconds for the DTS system to drop out of digital. Like Brad said, a flash once in a while is perfectly normal.

Posted by Richard May (Member # 2627) on 07-13-2005, 08:41 AM:

I know that it will not default until timecode is lost for 4 seconds. My question is what could be making it lose timecode at all. None of the other units that I work with are doing that. Also, the operators are saying that it is defaulting to analog. Everytime I watch it, it stays in digital but I have to assume that it is doing what they say.

Posted by John Walsh (Member # 168) on 07-13-2005, 11:37 AM:

How's the adjustable reference voltage inside the reader?

Posted by Bruce Hansen (Member # 281) on 07-13-2005, 12:40 PM:

Your opperators may THINK it is defaulting to analog, whenever the light blinks, but it takes 4 or 5 seconds of the light being out before the DTS unit defaults. Try cleaning the red LED and the lens of the reader. Check the gain adjustment (DTS calls it the LED voltage adjustment).

BTW, the other day, just to find out what would happen, I tried turning that adjustment slowly from one end of rotation to the other, at no time did the green time code LED go out. Leaving me to believe that the adjustment is not as critical as we may believe (but, it should still be done correctly).

Posted by Brad Allen (Member # 470) on 07-13-2005, 01:16 PM:

I had a dts timecode reader do as Richard has outlined. It did cause the sound to drop in and out of digital. The solution was to send the timecode reader in for repair. Problem solved.

Posted by Brad Miller (Member # 2) on 07-13-2005, 01:40 PM:

Guys, it even says in the manual that occasional blinking of the timecode light is normal and no need for concern. [Wink]

Posted by Michael Schaffer (Member # 1204) on 07-13-2005, 05:59 PM:

quote: Richard May
Also, the operators are saying that it is defaulting to analog. Everytime I watch it, it stays in digital but I have to assume that it is doing what they say.

Or you could assume that maybe they don't know the right terminology. Do they know how to interprete the lights on the DTS unit? Which ones go off when it reverts? What the main processor (which one, BTW) does? If it bugs you, stay after the last show, run the print again and make short droputs yourself by inserting a business card or other piece of stiff paper (but no plastic cards - scratches!) for a split second, half a second, 2 seconds etc. and observe the behavior of the system.

Posted by Richard May (Member # 2627) on 07-14-2005, 08:31 AM:

Brad, I know that it may occasionally blink. If they say though that it is switching to analog, then there is something wrong. Michael, they did observe the optical processor switch back to SR when it happens. I just wish it would do it when I was there. Also guys, 99% of the time the light stays on bright. It's almost like the timecode disappears on the film for a second.

Posted by Bruce Hansen (Member # 281) on 07-14-2005, 09:18 AM:

I have also seen grounding problems cause the reader to malfunction. Try losening the screws that hold the reader in place, and then tighten them again. If you have a scope, look at the output of the reader.

Posted by Brad Miller (Member # 2) on 07-14-2005, 10:40 AM:

What kind of projector is this dts reader running on? The belt tension on a Christie projector can actually affect dts tracking if it is too loose or too tight, much in the way that the belt tension will royally screw up an SRD basement reader on a Christie projector.

Posted by Frank Dubrois (Member # 3042) on 08-07-2005, 04:30 PM:

We had the same problem, however, the problem was solved by simply turning the voltage up on the reader.

Brad, how does belt tension affect the dts reader? I'm curious. Do the belts have to be WAY to tight or WAY to loose for that to affect the reader? I know Christie doesnt really give an "exact" way to achieve perfect belt tension, so I'm interested to know if this could be affect our other readers.

Thanks

Posted by Brad Miller (Member # 2) on 08-07-2005, 05:29 PM:

If the belts are too loose, they will "jump teeth" when the machine is started or turned over by hand. Obviously you don't want that.

If the belts are too tight, they can cause the entire machine to shake which can cause the dts to mistrack. (This also obviously prematurely wears the belts and pulleys too.)

You want them as loose as possible without any chance of them jumping teeth on the pulleys.

Posted by Monte L Fullmer (Member # 2797) on 08-07-2005, 06:34 PM:

quote: Brad Miller
You want them as loose as possible without any chance of them jumping teeth on the pulleys

..I've always done the quarter-inch deflection on those belts-the deflection before noticing the belt tightening between the sprockets. One needs to press down on the belt that is between each sprocket to measure this deflection.

Had a few readers that would blink on occasion, but some would say off for a few seconds, enough to allow the sound to drop back into optical. I would then realign the scanner roller a bit and it would track back into play by taking off that seal sticker, and tweeking the pivot screw. Sometimes, you have to do that even though the sticker mentions factory alignment. Done this many times...

If old readers, the LED voltage probably needs to be cranked up a bit by taking off the cover and with a "tweeker" screwdriver, turn up that small trim pot up a bit with a VOM across the LED leads to get your 4volt adjustment range.

-Monte

Posted by Mark Gulbrandsen (Member # 72) on 08-07-2005, 08:01 PM:

quote: Monte L Fullmer
turn up that small trim pot up a bit with a VOM across the LED leads to get your 4volt adjustment range.

This is done without film threaded through the reader!! Its not adjustig the LED per say its a gain adjustment for the preamp that you're actually tweeking. This adjustment compensates for LED fading.

Mark

Posted by Frank Dubrois (Member # 3042) on 08-07-2005, 08:29 PM:

Since were on the voltage topic, I noticed the last time I adjusted the voltage, the highest it would go is about 3.5, thats maxed out and with out the film running. When the film was running through, they drop to about 1.1. Is that normal? This is all the readers, not just one particular unit.

Posted by Mark Gulbrandsen (Member # 72) on 08-07-2005, 08:36 PM:

Then the LED is at the end of its life span. Both Gord Mc and myself are about to come up with an LED replacement for this reader. The number of 200.00 plus reader exchanges that I do for the sake of a 1.00 LED is approaching the rediclous point. Up north of the border the extra amount for duties and such are on top of that making it all the more rediclous.

Mark

Posted by Frank Dubrois (Member # 3042) on 08-07-2005, 08:57 PM:

I have to agree. Replacing the whole reader for the LED is just a poor design. Is replacing the LED something any semi-kowledgable projectionist can do, or will the unit still have to be calibrated/adjusted.

Also, about my last post, is it not normal for the voltage to drop to about 1 when the movie IS playing? Our units are about 5 years old.

Posted by Bruce Hansen (Member # 281) on 08-07-2005, 09:15 PM:

quote: Frank Dubrois
the highest it would go is about 3.5, thats maxed out and with out the film running

There must not be film in the reader when the adjustment is done. TP1 is on the reader side (after the first op amp), so if there is film in the reader, or dirt on the LED or lens, it will effect the reading. Also shining a light into the reader will effect the reading. When there is film moving through the reader, you will find square waves on TP1. A DC meter reading of the square waves on TP1 is meaningless.

Posted by Frank Dubrois (Member # 3042) on 08-07-2005, 09:23 PM:

Our lenses are clean. With no dirt, no film in the reader, I should be able to turn the voltage up PAST 4 without maxing the POT out. 2 of our units seem ok...the others get maxed out at 3.5....I was told that 3.5 is still fine. When the units were installed, the installer set them all to 2.0 Why? I know the LED gets dim over time. Does a new LED only need 2 volts where an older LED needs more juice to get the job done? Curious...

Posted by Michael Schaffer (Member # 1204) on 08-07-2005, 09:31 PM:

quote: Monte L Fullmer
I would then realign the scanner roller a bit and it would track back into play by taking off that seal sticker, and tweeking the pivot screw. Sometimes, you have to do that even though the sticker mentions factory alignment.

If you had good luck with this, OK, but it is definitely not something I would recommend for general practice. There is a reason for the sticker being where it is. To really align the reader properly, you need a special test film which, unfortunately, can not be bought. However, the reader dealigns itself rarely, I would say. But I wouldn't recommend people in general to peel the sticker off and play around with the reader.#
Since there is no error rate display (I think the DTS-XD10 has something like that, but I haven't worked much with that unit yet) on most DTS units in the field, there are too many imprecise variables to troubleshoot the readers and systems when you have bad timecode situations. Having people play around with them without proper testing equipment is about the last thing I would want...

Posted by Richard May (Member # 2627) on 08-07-2005, 09:37 PM:

Thanks for all your comments about this problem. One thing I think everyone is missing here is the fact that 90% of the time, the light is perfectly steady and super bright. If it was a low LED, I would think that it would be blinking more often and not as bright.

Posted by Mark Gulbrandsen (Member # 72) on 08-08-2005, 02:02 AM:

quote:
I was told that 3.5 is still fine. When the units were installed, the installer set them all to 2.0 Why? I know the LED gets dim over time. Does a new LED only need 2 volts where an older LED needs more juice to get the job done? Curious...

| IP: Logged

Franbk,
Again, you are not adjusting the LED voltage at all. The LED voltage remains constant thourghout the LED's life span but it does fade. Its the preamp gain that you are adjusting with the pot. 2.0 is dead wrong and your tech ought to be shot. Re-adjustment of the gain pot required more often and the processor might not get good time code on a dense print. Get a different tech!

Mark

Posted by Bruce Hansen (Member # 281) on 08-08-2005, 05:12 PM:

OK, here is a question for Mark, and everyone else here. I have not heard anything about LEDs losing intensity over time, but than again, what manufacture would want to talk about something like this? They are solid state devices, they either work, or they don't. The multi element LEDs used for Dolby Digital and optical readers can lose over all intensity when indivual LED elements die (if for no other reason than they are run quite "hot"), but the LED elements either work or they don't. I did a google search on this subject, and the only thing I could find was about how LED flashlights lose intensity as the batteries die (dah). So, does anyone have any information or data on LED intensity over time?

Doing some quick math, there is only about 8ma flowing through the red LED in a DTS reader. The red LED and it's current limiting resistor (R15 360 ohm) are directly across the 5 volt supply to the reader. Say there is a 2 volt drop across the LED (some what normal for a red LED), there would be 3 volts across the resistor. By ohms law: 3v/360ohms = 8.333ma. This would be will below the maxim rated current for the LED, and it would not get hot (the major cause for falure of solid state devices).

So, if the LED is not changing intensity over time, what is the cause of the problem with the reader not being able to produce that 4 volt reading at TP1? Is the LED getting skuffed, and the light is being defused? Is the alignment changing? Is the solar cell losing sensitivy over time, or just getting dirty (too many farts in the booth)? The MAX474 dual op amp is also a solid state device, and should either work, or not work (me thinks). One of the major problems with electronics today is electrolitic caps losing the moisture in the electrolite over time, and losing "value". There are two of these caps before TP1 (C3 and C8). I could see C8 losing value, causing a loss of level. It would be interesting to measure the light output of the LEDs in a "good" and "bad" reader. I have a feeling that DTS knows the answer, but is not going to tell us. So let's put our heads together, and figure this out.

Another thing to think about, since the LED is run well below it's max rating, could you change the value of R15 to allow more current to flow through the LED, and produce more light (if you cannot produce that 4 volt reading at TP1? If you put a 470 ohm reistor across the 360 ohm resistor that would give you about 15ma through the LED, and more light out of the LED. Could this keep your reader working for a little longer? LEDs of this type are usually rated for 20ma or more.

Posted by Frank Dubrois (Member # 3042) on 08-08-2005, 06:10 PM:

Its a good question, I'd like to hear a good answer. I, personally, dont think that boosting the power would be a great idea. I would think that it could have some effect on the sound quality. I'll be watching this. Although the voltage reading in our readers is decreasing, the LED looks as intense as it did on day 1. Also, when turning the voltage up/down, the apparent intensity of the LED doesnt seem to change. The movie will no long play in DTS, however, the LED is still on and bright. Hmmmm....this is an interesting topic. Can't wait for an answer!

Posted by Bruce Hansen (Member # 281) on 08-08-2005, 06:28 PM:

quote:
I, personally, don't think that boosting the power would be a great idea. I would think that it could have some effect on the sound quality.

The reader is just reading time code. Allowing more current to flow through the LED would not effect sound quality. The audio is stored on the CD ROMS.

quote:
Also, when turning the voltage up/down, the apparent intensity of the LED doesn't seem to change

The adjustment (R16) does not change the voltage (or current flow) through the LED, it adjusts the gain of the reader side of the time code reader. LEDs are current operated deivces, not voltage operated. They are diodes (the D in LED), and are therefore avalanche mode devices. Once the P/N junction brake over voltage is exceeded, an LED will go into very heavy conduction, if the current is not limited, the LED will burn out right away. That is why there is a current limiting resistor in series with LEDs, in this case R15.

Posted by Steve Guttag (Member # 268) on 08-08-2005, 07:03 PM:

LEDs do indeed loose intensity over time. Who ever said they are so stable as to just work, or not?

If you ever saw a Dolby multi segement LED loose a segment, you'd know it...first off it would look odd and second off...the mistracking on the 2:4 decoder would be quite dramatic.

I had much less problems with my DTS readers fading than my Dolby Digital or analog readers.

You are correct though...the harder your run them (higher current), the more they deteriorate. Note too, this is not as predictable as you might think. I've had some that got Brighter over time...some last a real long time...others that just seem to start going downhill from the word go.

Posted by Michael Schaffer (Member # 1204) on 08-08-2005, 07:38 PM:

Can that be cause by impurities in the doting?

Posted by Mark Gulbrandsen (Member # 72) on 08-08-2005, 08:01 PM:

quote: Michael Schaffer
Can that be cause by impurities in the doting?

Michael,

I think you mean impurities in the doping stage. Doping is just one stage of making a semicondictor......

One problem I've noticed is that the LED on the DTS reader is nopt "thermally connected" to its mount(or heat sink) and I believe this is one reason why I've seen some of these units LED's decay so quickly. On my last service trip through Montana the reader at West Yellowstone wouldn't even make 3.6 volts and it had a 2003 date on it. Now that theatre only runs one show a day there too! Ditto for one of two readers that had to be replaced in Idaho Falls. The other one was still of the non-adjustable type and had also quit reading time code reliably. I probably see on average anywhere from 3 to 6 readers a month that our customers have had to pay in excess of 200.00 each for when all that was wrong was a faded out $2.00 LED. The labor to replace it is about 1 to 1.5 hour shop time or in our case $65.00 an hour plus the $2.00 LED. Its pretty clear that DTS is taking ALL of us for a big ride on this simple and what should be a really inexpensive to repair problem.

quote: Bruce Hansen
Another thing to think about, since the LED is run well below it's max rating, could you change the value of R15 to allow more current to flow through the LED, and produce more light (if you cannot produce that 4 volt reading at TP1? If you put a 470 ohm reistor across the 360 ohm resistor that would give you about 15ma through the LED, and more light out of the LED. Could this keep your reader working for a little longer? LEDs of this type are usually rated for 20ma or more.

Bruce,

You're exactly correct and this is a big defficiency in that reader. Its obvious that it was kept as inexpensively as possible to produce and you could certainly change the resistor or insert a small pot in there to keep the led useful until the end of its life span. This is exactly what we do with the 24 segment Dolby LED's!! However I am not out to change DTS's circuitry but just make LED replacement inexpensive and very feesable to do at least in the shop.

Mark

Posted by Frank Dubrois (Member # 3042) on 08-08-2005, 09:28 PM:

So what would be involved in squeezing out a little more life? DTS was adament about taking the reader off, sending it in and (in the mean time) get a replacement. Big $$ for such a little problem. I'd be interested in getting a cheaper fix. Keep me informed.

Posted by Michael Schaffer (Member # 1204) on 08-08-2005, 10:35 PM:

quote: Mark Gulbrandsen
I think you mean impurities in the doping stage. Doping is just one stage of making a semicondictor......

Isn't the injection of minority carriers into the P or N material called doting in English? Doping? I thought it was "to dote" because in German in it is "dotieren".

Posted by Bruce Hansen (Member # 281) on 08-10-2005, 06:59 PM:

OK, it has been a LONG time since I studied this stuff, so someone correct me if need be. Pure silicon does not conduct current. Doping is the process of adding another substance to the silicon to allow it to conduct. To form "N" silicon, the substance that is added has an excess of electrons in it's outer electron shell of it's atoms. "P" has a deficiency of electrons in the atoms outer electron shell. This is referred to as "holes". Minority carriers are "impurities" that have the opposite condition. For example, having an atom with a "hole" in the "N" area. Heat can cause minority carriers, and then the minority carriers can cause more heat, and on, and on. This is called thermal runaway, and can result in the destruction of the device.

Here is how an LED works. "N" and "P" materials are joined together (or formed together). The area where the "N" and "P" areas are joined is called the junction. Foward current flow forces electrons from the "N" area to move across the junction and combine with an atom that has a "hole". In order to get through the junction the electron must take on extra energy from the current flow through the LED. This forces the electron into a higher energy electron shell. After it crosses the junction the extra energy is no longer needed, the electron drops back to it's normal shell position, and the extra energy is given off as a photon, which is a partical of light. An electron comes into the "N" area from the current frow into the diode, moves through the diode, then out the other end, and back to the power source. In a normal diode the extra energy would be given off as heat.

[ 08-15-2005, 05:28 PM: Message edited by: Bruce Hansen ]

Posted by Alexander Alves (Member # 1746) on 08-11-2005, 06:54 AM:

Could'nt one just try and short the small black wire with the tag at the reader cable end to the reader itself? This black wire come heat shrink wrapped I think.One could just loosen one of the reader allen screws and connect this wire there.

Posted by Bruce Hansen (Member # 281) on 08-11-2005, 09:14 PM:

Yes. That wire is there in case you have grounding problems. Grounding problems can cause noise in the time code, and make it hard for the player to read the code.

Posted by Mark Gulbrandsen (Member # 72) on 08-12-2005, 01:08 AM:

I am awaiting some samples of an LED that will probably work just fine. Will install one and make some tests and comparisons to a brand new reader and so on and so forth. Will let you all know.

Mark

Posted by Mark Gulbrandsen (Member # 72) on 08-16-2005, 05:40 PM:

I received my sample LED's today and installed one in a reader. Its about an hour job [thumbsup]

. The darn thing is too bright at 9 mils so I will have to change the series resistor to get down to 5 or 6 mils. Am also considering a 10 turn pot in place of the fixed resistor to be able to extend the LED life a bit. More tommrrow.

Mark @ CLACO

Posted by Mark Gulbrandsen (Member # 72) on 08-22-2005, 07:56 PM:

Since the LED that Gord and I chose to use was considerably brighter than the DTS factory LED I ended up installing a small 10 turn pot in series with the current limiting resistor that was there. Installation was very easy. Now the LED is running at about 4 mils and works perfectly providing the same brightness as a new factory LED but operating this LED at much lower current. The manufacturer sent me some MTTF data and at 5 mils its 100,000 hours life span to 80% brightness level. So even after 100K hours I can bring the current up to say 10 mils and maintain the proper brightness of the LED for a very, very long time. The new LED is good running up to 20 mils. To ensure exact alignment of the drum which has to be removed to replace the LED I used a very accurate height gauge and measured off the inner flange and then upon re-assembly put the drum back at exactly the same position within .001". Works like a charm!

Mark

Posted by Jim Ziegler (Member # 86) on 08-23-2005, 10:50 PM:

So can we send our dying DTS heads to you? [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 08-24-2005, 09:10 AM:

Sure, would be happy to repair yours. So far Gord will be doing them north of the border and I am doing them here in the states. The whole thing that brought this on was the rediclous amount that Gords customers were having to pay in duties/taxes to get them back over the border once repaired. Needless to say DTS'S rediclous price for changing the less than $3.00 LED also gave us some incentive to do this.

We are charging a 100.00 flat rate to re-led them at CLACO, this inclcudes a 1-year warrantee on the repair. You need to check the small board inside the front of your TC reader before sending it in to us. Your board MUST have the small white adjustment potentiometer on it.

Mark

CLACO Equipment And Service
1212 South State St.
Salt Lake City, UT
84111
801-355-1250 Office
801-355-1259 Fax

Posted by Brad Allen (Member # 470) on 08-24-2005, 03:56 PM:

Just curious, what does DTS charge for this?

Posted by Gordon McLeod (Member # 33) on 08-24-2005, 04:19 PM:

DTS charges 250 US i believe which is reasonable the problem we run inot is sending them one at a time through customs and getting the brokerage charges they really add up

Posted by Demetris Thoupis (Member # 833) on 08-24-2005, 05:02 PM:

Unfortunately something that I believe was never noted, COPIED DTS Discs. It happened here. DTS Does not work. I go with the Test discs, everything seems fine. Couple of days later the same problem occurs. After a week of investigation, that theater was copying the DTS discs and the copies did that exact same problem. The Reader blinking irregularly, drop-out every now and then and DTS comeback creating a disturbing come and go situation.
D

Posted by Mark Gulbrandsen (Member # 72) on 08-24-2005, 05:31 PM:

quote: Gordon McLeod
DTS charges 250 US i believe which is reasonable

The customer engineer that I spoke to when selectng the LED we are using called it rape! I've always felt that charging 250.00 for replacing a $3.00 LED was just a little bit absurd.

Demetrius, I assume that your 4 volt setting in the TC reader is correct.....

Mark

Posted by Gordon McLeod (Member # 33) on 08-24-2005, 05:44 PM:

If you have older disk drives they often have issues with burned disks

Posted by Brian Hogan (Member # 940) on 08-24-2005, 05:54 PM:

any ideas on how to unscrew those screws on the front panel of the reader head if they are stripped? im tryin to recheck my voltage and i get no grip with the key when i try to unscrew them. seems the service tech went a bit nuts the last time he was here on them.

Posted by Mark Gulbrandsen (Member # 72) on 08-24-2005, 07:57 PM:

I have a reverse helix set of drill bits that I use for that sort of problem. They're made by Greenlee. Just drilling them out is another option and then there is enough screw thread left that you can unscrew them with a small pair of nippers. If you run the drill place the reader cover screws in a down position so the metal shavings fall away from the reader and not into it. Replpacing themm with regular 4-40 alllen screws is a good idea since the hex is deeper and doesn't strip out nearly as easily.

Mark

Posted by Steve Guttag (Member # 268) on 08-24-2005, 09:51 PM:

Mark, it isn't necessarily the cost of the part but the time it takes to change the part. I haven't done a DTS reader but some LEDs seem to be installed with the thought of never changing them. Perhaps it would have been better if they redesigned their reader to have a better guidance system...a flywheel and an easy to get to LED.

Posted by John Hawkinson (Member # 1135) on 08-24-2005, 10:06 PM:

I don't remember, these are allen screws? If so, a good trick if to try nearby metric sizes, as well as to try Torx sizes. Because the torx wrench is tapered, it will fit into odd-sized hex holes and bite.

This is not terribly repeatable -- if you get it out, don't put it back. And not the best thing in the world for your torx wrench, though if you're careful it's not a big deal.

--jhawk

Posted by William Hooper (Member # 71) on 08-25-2005, 02:51 AM:

In a rush, you can find a screw extractor (a.k.a. 'easy-out') at an auto parts store. They're sold in various sizes.

Posted by John Hawkinson (Member # 1135) on 08-25-2005, 03:26 AM:

err.... If you think you're going to use a screw extractor correctly on the
first try, and in a rush, well, think again. They end up being insanely persnickety and tricky. Find some piece of scrap to practice on. And don't vary from the recommended pilot drill size unless you absolutely have to.

--jhawk

Posted by Mark Gulbrandsen (Member # 72) on 08-25-2005, 09:23 AM:

quote: Steve Guttag
Mark, it isn't necessarily the cost of the part but the time it takes to change the part. I haven't done a DTS reader but some LEDs seem to be installed with the thought of never changing them. Perhaps it would have been better if they redesigned their reader to have a better guidance system...a flywheel and an easy to get to LED.

The LED'S are siliconed in place and extracting that stuff with an ex-accto knife is an easy thing. What is a 90 min replacement time for me is a ripoff at 250.00 from DTS. I've done two of them now and after a couple of more replacements I may be able to get it down too an hour. Don't forget that I'm also adding a 10 turn pot to be able to adjust the LED current and replacing the LED. The LED I use will also outlast theirs by about a factor of 20. Yes, the TC reader SHOULD be re-designed for sure.... it is and was a poor design from day one.

quote: William Hooper
In a rush, you can find a screw extractor (a.k.a. 'easy-out') at an auto parts store. They're sold in various sizes.

Actually using an extractor below about 10/32 in size is a waste of time. Typically the extractor is so weak that it also snaps off.... and then you need to drill a pilot hole in hardened material..... not easy when its that small. Best thing is to just drill off the round head of the allen screw... then there is about .060 left that you can grab with a small pair of nippers and just unscrew it. For what ever reason those black oxide screws like to stick to the black aanodize and can sometimes be a pain to get loose. Just don't do this whith the reader in position on the projector and keep any particles from going inside the reader.

Mark

Posted by Michael Schaffer (Member # 1204) on 08-27-2005, 05:16 AM:

quote: Mark Gulbrandsen
What is a 90 min replacement time for me is a ripoff at 250.00 from DTS.

But Mark, isn't your hourly rate $400?

Posted by Mark Gulbrandsen (Member # 72) on 08-27-2005, 07:48 PM:

No, We only charge that rate for platter motor repairs that come in from California [Smile]

.... The rest of the States get billed at 65.00 per hour......

Mark

Posted by Frank Angel (Member # 248) on 08-28-2005, 05:50 AM:

Knowing now that this is a problem, those of us who have screws that aren't yet stripped would be smart to replace them with regular philips or even good quality hardened slot or philips screws. Preventative maintenance.

Posted by Frank Dubrois (Member # 3042) on 08-29-2005, 01:40 AM:

A new twist...what if you have one stripped out screw and there is NO room to get even a screwdriver size tool in there to remove it? Some of our units are placed so close to the wall, that an allen wrench BARELY fits. I know we can move the projector back...but seriously, theres gotta be another way.

Posted by Mark Gulbrandsen (Member # 72) on 08-29-2005, 04:27 AM:

Try removing the reader off its mount atop the projector!!

Posted by Monte L Fullmer (Member # 2797) on 08-29-2005, 04:31 AM:

yea..two phillips screws, undo the data cable with a small flatblade screwdriver and it'll plop in your hands....(just remember which two mounting holes that were used that mounted that reader...)

-monte

Posted by Gordon McLeod (Member # 33) on 08-29-2005, 10:10 AM:

I would never replace an allen screw head with a phillips since they are more prone to stripping Also the allens are cap head

Posted by Mark Gulbrandsen (Member # 72) on 08-29-2005, 08:51 PM:

Yes, If you just replace them with standard grade allen screws, not the factory cap style you will find the hex part of the standard screws more durable because its deeper than it is on a cap screw. when we do the LED replacement we also replace those cap screws!!

Mark

Posted by Steve Guttag (Member # 268) on 08-30-2005, 06:18 AM:

They use "cap" screws? I thought they were "button head" screws.

Posted by Mark Gulbrandsen (Member # 72) on 08-30-2005, 06:22 AM:

Cap head, button head... all the same. Crap head would certainly be more fitting!!

MArk

Posted by Ron Yost (Member # 1850) on 08-30-2005, 11:59 AM:

They're all cap screws...socket head cap screws...as opposed to hex head cap screws (ordinary bolts).

See the various socket head types and their designations here:
Socket head screw info

Ron Yost

Posted by Steve Guttag (Member # 268) on 08-30-2005, 12:34 PM:

I'll conceed that they are all "cap" screws in that they are capped (as opposed to a set screw that does not have a cap) but in common reference, a "cap" screw referrs to the cylindrical head version. You'll note that on your reference page, the "button head" screw does not have the "cap" in its name since it is adequately defined at that point. I can't remember the last time one referred to a hex socket cap screw as a "cylindrical head hex socket" When one calls out a hex-cap screw, that is what most people picture in their mind.

As to your reference...it isn't correct in its language either...a "Bolt", by definition, comes with a nut. A screw is a bolt without the nut. Some mistakenly refer to larger screws as bolts or smaller screws as machine screws...the distinction is just whether it comes with the nut.

How this helps with the DTS fastener issue is beyond me. [Cool]

I have not had problems with button head screws, myself and like them for many shallow fastener needs or to have a lesser appearence. I presume DTS used them in this application so as not to call attention to the fasteners (they blend in with the brushed face plate better than cap screws would). Functionally, caps will work every bit as well.

Personally, I wish DTS would open up the hole around the 9-pin DSub...it is not tall enough to fit some connectors (Amp brand, in particular).

Posted by Gordon McLeod (Member # 33) on 08-30-2005, 12:56 PM:

I don't see the Robertson head in that catalogue [Smile]

http://www.mysteriesofcanada.com/Ontario/robertson_screws.htm
http://inventors.about.com/od/sstartinventions/a/screwdriver.htm

Posted by Mark Gulbrandsen (Member # 72) on 08-30-2005, 05:57 PM:

quote: Steve Guttag
As to your reference...it isn't correct in its language either...a "Bolt", by definition, comes with a nut. A screw is a bolt without the nut. Some mistakenly refer to larger screws as bolts or smaller screws as machine screws...the distinction is just whether it comes with the nut.