Hi hopе the rest of your stay was productive regarding uwphotos! As for the problem I had the same also during this New Year holidays. One YS-d2 (not J version) just stoped firing or I would say started firing intermittently (for ex every other third or forth time and with full power no matter what power setting i select (and to be more confused if I select the lowest power setting it did not fire at all!!!)).
So for now I am confused if I should buy a new J version and save some money or switch completely to Inon z330 (my wife using them and they work like a charm, they a more powerful (with my cause an overexposure in the shallows + large f-stop conditions ).
So what was your decision or a strobe problem resolution?