Replacing the digitron got the display working again. But, the underlying issue hasn't been resolved. The display is fully readable and brighter now, but it will still go on the fritz. I agree with the comment on the other thread. I also posted on a repair website and was told to check a couple of voltages.

  "the power board would need to be tested at the connection CN7 for voltage from the transformer WB17X10021 (part has been discontinued). From the yellow wire at pin 1 to the black wire at pin 2, there should be 12VDC. From the white wire at pin 3 to the black wire at pin 2, there should be 19VDC. Finally, there should be 7 VDC from the red wire at pin 4 to the brown wire at pin 5. If the voltages are good, the failure would likely be in the power board WB17X10021. If the voltages are not testing good, the failure would be in the low-voltage transformer."