Looking at the problems from last night I began looking at the ESD this AM.  Noticing that the main read back for driver was flickering on and off I by-passed the LV driver and looked only at the HV driver.  It was obvious the DC bias was not present.  Hoping it was not the Driver itself looked at the incoming DAC channels and all functioned except the DC bias channel.  Tracked it down to the output of the IO chassis.  Filiberto replaced the 18bit DAC, ribbon cable and interface card.  This cleared up the issue.  While working on this noticed the ESD can get into some odd states when the on/off switch is pressed.  I think we still have some binary issues that latch the unit up.  Was able to clear the problem by going to the BIO screen and changing states.