centerville,
you have had problems before, have you ever had an. ink spill?
if it were me i would, very carefully seperate the sub board from the main & clean all the connectors with a zero residue contact cleaner. (91% alcohol in a pinch, put be careful, it may remove markings (things like head rank)
carefully unplug line power after shutting everything down. walk away for 10 or 15 minutes
before opening the machine. follow the above instructions, lets check for fuses, anything not looking normal.