No light on LE channel

[IndianaChristmas]

I was testing out my LE's and found that channel 13 didn't work.  The LED for the channel lights.  All other channels supply power to a string of lights.
So my question is - if the LED for a channel lights on the board is the problem after the LED?  Meaning the problem is on the ouput side of the LED.  If so what is the most common cause?  I hope it isn't the mofset as that must be a bugger to get out.  I already checked cord for the light, the chip is seated properly.
Thanks,
Eric

[pk]

If the LED lights, then there are only a few parts that could be bad.  Check your solder joints around the opto, triac, and the CH 13 output connector on the terminal strip and make sure they are good. 

You can try swapping the opto with one from a working channel.  If that doesn't fix it then the Triac is probably bad.  I have never changed one that is mounted to the heatsink but from my experience here is my suggestion.  Remove the hardware for the Channel 13 triac.  Bend the triac away from the heatsink and cut the leads.  Heat the leads one at a time and pull them out with needle-nose pliers. Clean the solder out of the holes and put in a new triac.

Good luck

[Rainlover]

I have had a couple of triacs fail but they always left the channel constant on.

John

[tbone321]

Although that is the more common triac failure, they can fail in the open mode as well.

[IndianaChristmas]

I think it was a bad triac.  Will get another and find out.  The optical worked in a different position on the board so it wasn't that.  Solder points were redone with no luck.  I'm not worried out of all the units I've made only this one appears to have the triac issue.
Thanks

[jnealand]

I had to replace two triacs on one LE after the season ended last year.  It actually was not as bad a problem to remove as I thought it might be.  However I did remove the heat sink in order to give me more room to maneuver in order to remove the bad triacs.  Fortunately during the show I did have a couple of spare channels so I was able to just move the lights to another channel and tweak vixen.  I second the idea of cutting off the triacs as close to the board as possible and the heat remove the pins.  The Radio Shack desoldering tool is worth its weight in gold when doing this stuff.

[dannyct]

Having a spare channel on each LE is a great idea.  I am planning to have my first channel on 1st LE and the last channel on 2nd LE "open", in this way I would have all channels sequencing from 2 to 31  (no gap in between channels, which makes easier to program with Vixen).

I had to replace two triacs on one LE after the season ended last year.  It actually was not as bad a problem to remove as I thought it might be.  However I did remove the heat sink in order to give me more room to maneuver in order to remove the bad triacs.  Fortunately during the show I did have a couple of spare channels so I was able to just move the lights to another channel and tweak vixen.  I second the idea of cutting off the triacs as close to the board as possible and the heat remove the pins.  The Radio Shack desoldering tool is worth its weight in gold when doing this stuff.