I called Marc this morning and he headed out to site. Dave confirmed (86389) that the card that needs to be replaced is the one we swapped in a couple weeks ago (86086) while trying to solve the TMSX ASC locklosses (86079). Since the issues stopped after the old card was swapped out, we know that it was what was causing the issues. Unfortunately this means that that old DAC card won't be a good replacement for this failed card, so Marc is hunting around the EE lab looking for a different 18-bit DAC.