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Archer

Can it be a triac?

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I just visited the Hardware Forum and saw it had over 23,000 topics to research for my question. I decided to ask my friends here in the Coffee Shop. 

I have a controller with 2 bad channels. I know if a light stays on it is more than likely a bad triac? I have replaced triac's for channels and it fixed the problem of lights staying on. However, if a channel does the exact opposite and stays dark no matter the command can that also be a triac?

kevinkolak.com 

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To answer your question a triac can short,  lights staying on or it can stay open thus lights never coming on . I had the exact problem you are having with 1 of my  controllers approx 2 years ago. So i  replaced the  defective triac problem went away

Edited by Godney

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Thanks....I'll cut it out and replace it. Stay tuned for the answer....

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I replaced 2 triacs and the channel that was on all the time is now functioning properly. The channel that was off all the time is still off all the time so the triac was not the problem.....

It was worth the effort.....

kevinkolak.com 

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Could be this little item "400V Triac opto-isolator" the little white square thing before the triac.

They are not easy to replace.

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I'm up for the challenge....Wish me luck. What are the chances it is the problem knowing I already did the triac?

Thanks for your response! 

kevinkolak.com 

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I should go find all my posts on how why when Traics blow and what the causes are and PIN it.

As everyone has already said, 95% of the time when a Triac blows it only blows one side and you get the 50% on failure.  Of the remaining 5% 4.9% totally blow both sides of the triac for a 100% on.  That is pretty rare. That last .1% can blow at full off and stay full off - which is SUPER SUPER rare (but can happen).

I have to agree with Earl, I think you may have an opto that went bad, but again that is like a 1 in 10,000.  Before I went and started to pull it, I would trace all the way from the spade terminal on the board, thru the triac, thru the pull up resistor across the opto and then back to the PIC.  Touch up (reheat) all the pins and re-test.

Pulling the opto is going to be a bear if you don't have a good rework station.  It is not something I recommend you do unless you have the tools and the experience.

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I can appreciate what you are saying DevMike about getting those 6 pins out of the board but.....

I had it out and the next one in, in 10 minutes. There are 2 things that you must do simultaneously and they pop out 1 side at a time. The soldering iron must have a tip that cover all 3 pins on one side at the same time. While applying the heat you must be pulling from the topside with a small pair of needle nose pliars or my favorite is with a very small flat head screwdriver pry up lightly using a neighbor as a fulcrum. Be careful as when they let loose it's quick. Repeat the process for the remaining side except this time I preferred the needlenose plairs to grab hold of the already loose side and lightly pull while applying the heat to the remaining 3 pins. Now that it's out, the holes still have solder in them.....simple fix. While heating them blow them out with compressed air. The same compressed air you use to clean your computer keyboard or other electronic equipment. They then look as clean as when new.

Having done all of the above my channel is still dark....now what?

kevinkolak.com 

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43 minutes ago, Archer said:

I can appreciate what you are saying DevMike about getting those 6 pins out of the board but.....

I had it out and the next one in, in 10 minutes. There are 2 things that you must do simultaneously and they pop out 1 side at a time. The soldering iron must have a tip that cover all 3 pins on one side at the same time. While applying the heat you must be pulling from the topside with a small pair of needle nose pliars or my favorite is with a very small flat head screwdriver pry up lightly using a neighbor as a fulcrum. Be careful as when they let loose it's quick. Repeat the process for the remaining side except this time I preferred the needlenose plairs to grab hold of the already loose side and lightly pull while applying the heat to the remaining 3 pins. Now that it's out, the holes still have solder in them.....simple fix. While heating them blow them out with compressed air. The same compressed air you use to clean your computer keyboard or other electronic equipment. They then look as clean as when new.

Having done all of the above my channel is still dark....now what?

kevinkolak.com 

Hoping the solder doesn't land across two terminals and short something, when starting 

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A quick recap of events....

2 bad channels, 5 and 13

1 alway on (13) and one always off (5).

Replaced 2 triacs and the channel that was always on (13) is now working properly. The channel that was dark (5) remains dark or off.

Replaced the "opto" and the channel 5 still remains dark or always off.

What's next?

kevinkolak.com 

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I'm hoping it wasn't just a channel he forgot to sequence  :D

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Mr P

I take it you have never used the Hardware Utility....sequencing does not apply.

kevinkolak.com 

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Never seen an LOR controller, so not sure if they use standard Resistors or not. If they do, Check them.

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just send the thing to me and forget about it.. Let it become my problem and order yourself a new one.

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I have about 50 controllers and only recently have I purchased them assembled. The first 40 or so were the DIY kits, I know all about putting the "opto" in the right direction but you made me look and ?.

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20 hours ago, Archer said:

 

I can appreciate what you are saying DevMike about getting those 6 pins out of the board but.....

I had it out and the next one in, in 10 minutes.

 

 

On 11/17/2016 at 2:05 PM, DevMike said:

 It is not something I recommend you do unless you have the tools and the experience.

I guess you had the tools and experience then.

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DevMike....I'm 65 and been down a few roads in my life. I have put together 40 of these controllers and I confess it was not a flawless effort in the beginning . You only have to take 1 "opto" out to realize there has to be a better way. As you know, heating 1 pin and moving it 1/1,000th of an inch is enough to make you finish the job with a claw hammer. So with a little thought, I tried heating all the pins on one side and BINGO.....it popped out so fast it surprised me. In fact it bent the pins still in the board at almost 90 degrees it was so fast. Using that knowledge when I heated the other side, they cam out straight because I was expecting it. I hope others use what I am writing to good use and theirs will come out just as easy. The compressed air trick is also a great suggestion as it can be just as aggravating getting the holes clean.

Having said that....my channel 5 is still dark. I'm ready for more suggestions.

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You could have installed a bad component. Other possibility is overheating while your soldering it in. You wouldn't be the only person who fried a component while putting it in:wacko:. the optocoupler can be very sensitive to heat. This is where a scope and a good volt ohm meter with somebody who knows how to use it comes in handy.

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Thanks Drew....but I guarantee you that I had less heat by doing all 3 at once than by doing them 1 at a time.....I've done it both ways.

Skip the wick in this case until it is out and all you want to do is clean up the board. I'll remove the one I put in and put a different one in its place....I have nothing to lose.

 

Keep I mind that I have installed 640 of these opto components in 40 controllers over the last 4 yrs. This controller worked fine for at least 3 seasons.

Edited by Archer
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No more suggestions?

kevinkolak.com 

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I'd start metering from the triac back by staring and comparing to a channel next to the non-working one. I've had bad solder joints in the past so good light and a magnifying glass could be helpful.

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There are a couple of resistors to check.  I believe there is one between the opto and the triac.. There should also be one on the front side of the opto from whatever logic device is driving it.  The output is a pretty simple configuration.  Logic driving the opto's LED via a current limiting resistor and the output side of the opto driving the triac, usually via a resistor.  That is about it.  There could also be a PCB land that has a fracture that you can't see.  An ohm meter will tell you what you need to know.. I assume by your posts that will not be an issue for you to check. 

 

Craig

 

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I always second guess myself that continuity will come from another direction. Or are you saying I should read the value of the resistor if it is good?

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