Channel not working

[ken collins]

I have a spare board, built a few years back, that had a channel stuck on, and one that didn't work (ch 13)The channel stuck on was just a bad triac, but while repairing that, I put a new triac and opto on chan 13, and still doesn't work.

Just looking for a direction to go.

[ErnieHorning]

If this is a 16 channel board, I would try swapping the to micro's. Since they're in sockets, this would be quite easy.

If channel 13 works, you may find that channel 6 no noger works, indicating a bad micro.

You may also find that its a bent micro pin on the bad side.

[ken collins]

Even if that doesn't work, I'm putting it in my book Thanks

[-klb-]

Start tracing back from the triac, looking for cold solder joints.. Maybe just reflow the solder on the triac, opto, resistor near those two, the appropriate one of the 4 resistor packs, and the latch on that side of the board...