Epson AcuLaser C8500 Service Manual page 288

EPSON AcuLaser C8500
NOTE: Carry it out again from the beginning after you confirm
connection condition and so on if a [Error] message is indicated.
Exchange MCU PWB, and confirm it when even the practice of
the re-occasion becomes a "Error" message.
Communication Error
Verify Error
Chapter 4 Diagnostics
Revision C
4-20