I can't see the revision number but am guessing that is my current version since the potting is higher than the first fused units I made. So I guess the flashing (three flash sequence) was occurring. That missing pin conducts the current of both fans so it really got hot to melt the solder. The fact the fuses also got hot tells me it was not just a bad connection on that missing pin. I would suggest you replace your fans ASAP.
It's funny some owners have no problems (yet) running OEM fans and some owners have their fan fail jumpers melt and catch fire.