triac?

[duane.mosley]

had a dead short and blew a fuse, now 2 channels are stuck on. if I remember correctly, that is a triac issue correct?


thanks

duane

[tbone321]

Not always but in this case, the chances are pretty high.  You can always pull the opto's for those two channels and power it back up and if the channels stay on, then the triac's have fried and shorted and need to be replaced.  The only issue I have is why did two of them fail?  It really should have just been the one with the shorted connection.

[duane.mosley]

Not always but in this case, the chances are pretty high.  You can always pull the opto's for those two channels and power it back up and if the channels stay on, then the triac's have fried and shorted and need to be replaced.  The only issue I have is why did two of them fail?  It really should have just been the one with the shorted connection.

I believe the short occurred on those two channels. I was moving things around and poof! I haven't dove in yet to see what happened. it was late so I just went to bed. I do notice that the leds on the board for those channels are not lit if that means anything. will dig in here in a bit and figure it out.

[tbone321]

The LED's simply indicate which channels the PIC is turning on.  Being off means that the PIC is not trying to turn them on which is what you would expect.  Removing the opto removes any driver from the triac and if it remains on, then the triac has shorted out.  If the channel turns off, then the problem exists elsewhere and is probably the opto itself.