Epson TM-U375 - Data from Host Is Not Printed Normally

4-7
7 Data from host is not printed normally (for the serial model) (*)
(*) See Chapter 7 for the parallel interface model.
7
Set SW1 of DIP switch bank 1 to OFF.
Is “?” printed?
Make settings identical.
Yes
No
OK ?
END
Yes
No
Check the host.
Replace printer mechanism assembly.
Send data from host to printer.
OK ?
No
Yes
Are RS-232C
interface parameters
set to identical values at
host and printer?
No
Yes
Yes
No
Is output voltage
of regulator on main PCB
within spec? (✽)
Does interface cable
match specifications?
Replace with a proper cable.
OK ?
No
Replace main PCB.
END
Yes
Is the interface
wire broken?
OK ?
No
Yes
END
Replace the interface cable.
OK ?
No
Yes
END
(✽) Verify the voltages shown in this
table:
Checkpoint Rating
RXD terminal (pin 3) of CN2 ±12 V
TXD terminal (pin 2) of CN2 ±12 V
END
No
Yes
Yes
No
CONFIDENTIAL