Epson TM-U220 Series Service Manual page 38

Confidential
Communication test fails
Table 3-19 Communication test fails
Probable part/probable cause
Communication condition
I/F cable
I/F circuit board unit (122)
Main circuit board unit (201)
Print result is not normal.
When print is light or irregular: Refer to page 3-11.
When print is dark: Refer to page 3-11.
When dots are missing continuously: Refer to page 3-12.
When line spacing is irregular: Refer to page 3-12.
When two-color printing is not performed, or the colors are mixed: Refer to page 3-13.
3-16 Troubleshooting
.
Checkpoints
Check the communication settings. Make
sure the settings printed by the self-test are
the same as the communication settings
shown by the service utility.
Check the I/F cable connection. Make
sure the I/F cable is plugged in securely.
Check the continuity with a tester. Make
sure no wires are cut or shorted out. Be
sure the cable is wired correctly.
Check the connection. Make sure the
connector is plugged in securely.
Check the parts for defects.
Check parts on the main circuit board unit
(201) for defects. Make sure connector
(CN1) is connected.
Action to correct the problem
Set the correct communication
settings. Completed if operation is
normal.
Plug in the I/F cable correctly.
Completed if operation is normal.
Replace the I/F cable. Completed
if operation is normal.
Connect the I/F circuit board unit
(122). Completed if operation is
normal.
Replace the I/F circuit board unit
(122). Completed if operation is
normal.
Replace the main circuit board unit
(201). Completed if operation is
normal
Rev.A