Had a previous SunControl board burn out and got a replacement. It worked for a few days but overnight after the sun went down it stopped functioning and on of the IC's was extremely hot. Put comments under prior threat (http://forum.switchdoc.com/post/6299/thread) but wasn't sure if that worked since it's a "new" problem (although same symptoms).
I can't see it's anything I'm doing given the simple hookup and the fact it was working for 2 days. I heard there were other instances of this reported, any news on it? How should I handle replacing this one?
Is your solar cell input protected by a Zener diode of sufficient amperage? If not then you can end up with a failure mode like you describe.
On a rather unrelated note - the SunControl board is very susceptible to water - I had made the mistake of putting the solar powered) exhaust fan at the side of the box which during a targeted rainstorm allowed a few drops into the box. That was enough to fry one of my SunControl boards , also in the fashion you describe. Lesson learned - in the new box I'll put the fan at the bottom.
I am running them through the the 1x4 suncontrol Mux board, which includes the diode on each leg. That said, I did have 4 different panels in bright sun running on a single mux,total output was in the 500ma to 900ma output, meaing the current hitting the diode in the reversa direction 0.9amp, so 3/4 of that was hitting the other diodes. I assume, since I got all the panels from them Switch, that the diodes were sized assuming maximum panel output on all 4 legs, but maybe not?