The pictures posted here
https://www.msextra.com/forums/viewt...?f=101&t=70950
shows that the J702T ignitor is not a true logic-level ignitor, but needs high current drivers. The wasted spark board uses a ATtiny24A chip, which probably can't reliably supply enough current and, over time, burns out.
Try using a different dual ignitor, or a pair of the standard Bosch ... 124 ignitors.