DiyLightAnimation
Hardware => Lynx Express => Topic started by: Brad on May 19, 2009,
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Hi All,
Fired up my 2nd LE last Sunday and had 4 ch's not working. #2,#13,#14,#15. Checked the bottom for cold solder joints. Lifted a couple opto's to check for bent pins, all okay. Made sure all opto's were seated properly.
Any thoughts?
Brad
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Hi All,
Fired up my 2nd LE last Sunday and had 4 ch's not working. #2,#13,#14,#15. Checked the bottom for cold solder joints. Lifted a couple opto's to check for bent pins, all okay. Made sure all opto's were seated properly.
Any thoughts?
Brad
Hi Brad
The four channels not working did you have light sets connected or just looking at the on board leds?
if just the leds I would bet they are in backwards (don't ask me how I know this :))
Oh, did you run the on board test mode?
Rick R.
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Rick,
I had lights attached. I used "all ch's on" in Vixen as well as had a 1 min sequence running. Nothing wrong there. LE #1 worked fine with the same sequence.
I will look at the LED's when I get home from work.
Brad
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If you are still having problems, can you post a pic of the bottom of the board?
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Let us know what you are seeing so we can help.
RJ
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I'm thinking I may have 4 bad opto's, but what are the odds of that? The low voltage side of the opto's all have the same level. The output side has 110v on pins 4&5, as you would expect, but only on the lit LED's. The ones not working have near 0V on pin 4 and 110v on pin 5.
Brad
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Forgot to attach pic.
Brad
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Well it's definitely not the optocouplers. I remembered I had 4 left over from last year. Tried em. Didn't fix the problem. Humm...I think the pic is next in line.
Brad
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Can you get a picture of the other side of the board too, where we can see the components?
Ron
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Sure
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I had a similar problem on my first LE build. I would try hitting the "problem" triacs again with the soldering iron. It also looks like a couple of resistor joints near channel 14 and 15 look cold.
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Memphis,
I see what you are looking at. I went over all joints from the limiting resistors, ahead of the optos, all the way to the output terminal blocks.
Brad
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I'm thinking I may have 4 bad opto's, but what are the odds of that? The low voltage side of the opto's all have the same level. The output side has 110v on pins 4&5, as you would expect, but only on the lit LED's. The ones not working have near 0V on pin 4 and 110v on pin 5.
Brad
So do all of the channel leds turn on in the test mode?
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I'm thinking I may have 4 bad opto's, but what are the odds of that? The low voltage side of the opto's all have the same level. The output side has 110v on pins 4&5, as you would expect, but only on the lit LED's. The ones not working have near 0V on pin 4 and 110v on pin 5.
Brad
So do all of the channel leds turn on in the test mode?
Yes this is my question also. If the leds for a channel are lighting the pic is doing its thing. The same current that turns the Led on also turns the opto on. If the leds do not light #1 to check is backwards led on that channel. Then the pic might be changed. Simple design so it will have a simple answer.
Catch me on teamspeak and we can walk through a complete test in a few minutes that will tell you exactly what is wrong.
RJ
BTW it might be the light fooling me but it looks like you have at least two of the 180 resistors on the bottom leg that look like they are unsoldered? check and make sure this is not correct.
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I'm thinking I may have 4 bad opto's, but what are the odds of that? The low voltage side of the opto's all have the same level. The output side has 110v on pins 4&5, as you would expect, but only on the lit LED's. The ones not working have near 0V on pin 4 and 110v on pin 5.
Brad
So do all of the channel leds turn on in the test mode?
Yes this is my question also. If the leds for a channel are lighting the pic is doing its thing. The same current that turns the Led on also turns the opto on. If the leds do not light #1 to check is backwards led on that channel. Then the pic might be changed. Simple design so it will have a simple answer.
Catch me on teamspeak and we can walk through a complete test in a few minutes that will tell you exactly what is wrong.
RJ
BTW it might be the light fooling me but it looks like you have at least two of the 180 resistors on the bottom leg that look like they are unsoldered? check and make sure this is not correct.
I sure hate when life gets in the way of my hobby's :(
I had to bail on the troubleshooting for a couple of days, cause of work obligations and yard work :( :(
Now that the lawn is mowed, fertilized, and looking good... I'll recap what I have tried.
1. Resoldered all joints in question from 330ohm resistor to terminal header.
1a. Verified all LED's are oriented correctly.
2. Replaced the 4 opto's with new.
3. Swapped the Pic with Pic from LE #1.
LED's #2,13,14,15 do not light up, nor does mini lights on these ch's.
Going to look over solder joints in the sunlight today. Hopefully I've missed something in the dark, dingy light of my cave.
Brad
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Ok lets try some good old directed troubleshooting.
Lets forget than anything is wrong except channel #2. What do we know. The LED does not light and the triac does not trigger power.
Well if the led does not come on and the LED is good and in the correct direction. Then we only need to fix the LED coming on. WHY? because the LED is a troubleshooting device as well as looking cool. It tells me that the opto is not being trigger so the triac should not be coming on.
With this said we have two possiblitys. One we are not getting the trigger pulses to the led to turn it on. (GROUND) or the power is not reaching the LED.
Check pin #3 of the pic chip for a good solder joint and that the pics pin is in the socket good and not bent.
Check the channel #2 led for good joints and that it is in correct.
check the 4th 180 resistor from the left looking at the top of the pcb. Look at the joints and verify that is is a 180 ohm and not a swapped 330.
If this is all correct then put your ohm meter on pin #3 of the pic chip on the top of the chip. Check for a connection to the led (-) side on the top of the led.
then check for a connection from the led (+) to the top of the 4th 180 ohm resistor (should read between 173 - 187 ohms) if not there is a problem there.
Let me know what you find with this.
Ignore the other channels work only on channel #2 for the time.
RJ
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RJ,
First of all thanks for the help. Got it fixed and running ;D
Still not sure exactly what the problem was. No continuity between 330 ohm and pin 3. Resoldered bottom, still no continuity. Resoldered from top, no continuity. Did again...still no continuity ???
Stuck a test lead between resistor and solder joint on bottom of pcb at pin 3. I got continuity ;D
Did the same on ch's 13,14,15, all LED's work.
Soldered jumper wires on effected traces every thing is good now.
Only thing I can think of is maybe the via's are not connected to the trace??
Again, thanks for the help.
Brad
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RJ,
First of all thanks for the help. Got it fixed and running ;D
Still not sure exactly what the problem was. No continuity between 330 ohm and pin 3. Resoldered bottom, still no continuity. Resoldered from top, no continuity. Did again...still no continuity ???
Stuck a test lead between resistor and solder joint on bottom of pcb at pin 3. I got continuity ;D
Did the same on ch's 13,14,15, all LED's work.
Soldered jumper wires on effected traces every thing is good now.
Only thing I can think of is maybe the via's are not connected to the trace??
Again, thanks for the help.
Brad
That concerns me. No sign of damage? the PCB's all get electrical tested at the PCB house so I would not expect this. Mail me the unit and if it is the board and there is no damage to it I will replace the kit for you.
RJ
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RJ,
I see no physical damage to the board. I'm fine with the board the way it is. I soldered jumper wire on the bottom side, and will secure it with RTV. No one will ever know it's there except you and
me :D
If, on the other hand, you need to see it for quality control reasons, I understand. But really, I'm fine with it.
Brad
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No one will ever know it's there except you and
me :D
and me. ;D