Epson TM-U220 Series Service Manual page 26

Confidential
ERROR LED flashes
Table 3-3 ERROR LED flashes
Probable part/probable cause
Home position detection error
R/W error in memory
High-voltage error
Low-voltage error
3-4 Troubleshooting
Checkpoints
Check for a paper jam around
the carriage. Make sure there is
no paper jam.
Check the tension of the
carriage belt (507). Make sure
the carriage belt has
appropriate tension.
Check operation of the parts
around the carriage by moving
the carriage from side to side.
Make sure the belt drive pulley
(505) rotates by moving the
carriage sub assembly (1025)
from side to side.
Check the resistance value of
the carriage motor sub assembly
(1034). Make sure it is 7.2 Ω or
less.
Check the operation of the HP
board assembly (518). Make sure
the signal changes when you
block the sensor.
Check the connection of main
circuit board unit (201)
connectors. Make sure they are
plugged in securely.
CN7: carriage motor sub
assembly (1034)
CN4: HP board assembly (518)
Check if the parts on the main
circuit board unit (201) have any
damage. Make sure connector
CN7 and U8 look normal.
Check for repeatability. Make
sure operation is normal by
rebooting.
Check the DC power voltage on
the main circuit board unit (201).
Make sure the power voltage
has the proper voltage rating.
(Refer to page 3-20.)
Check the DC power voltage on
the main circuit board unit (201).
Make sure the power voltage
has proper voltage rating. (Refer
to page 3-20.)
Action to correct the problem
Remove any paper jam. Completed
if operation is normal.
Adjust the tension of the carriage belt
(Refer to page 4-5). Completed if
operation is normal.
Install the carriage belt (507) into the
carriage sub assembly (1025).
Completed if operation is normal.
Replace the carriage motor sub
assembly (1034). Completed if
operation is normal.
Replace the HP board assembly
(518). Completed if operation is
normal.
Plug in the connectors securely.
Completed if operation is normal.
Replace the main circuit board unit
(201). Completed if operation is
normal.
Replace the main circuit board unit
(201). Completed if operation is
normal.
Replace the main circuit board unit
(201). Completed if operation is
normal.
Replace the main circuit board unit
(201). Completed if operation is
normal.
Rev.A