Epson TM-U220 Series Service Manual page 40

Confidential
Print result is not normal
Print is light or irregular
Table 3-11 Light or Irregular Print
Probable part/probable cause
Ribbon cassette
Ribbon take-up function
Adjustment roller shaft holders
(506)
Print is dark
Table 3-12 Dark Print
Probable part/probable cause
Adjustment roller shaft holders
(506)
Dots are missing continuously
Table 3-13 Missing Dots
Probable part/probable cause
Head FFC (521)
Print head unit (503)
3-12 Troubleshooting
Checkpoints
Check the ribbon mounting. Make
sure it is installed correctly.
Check the ribbon cassette. Make sure
the ribbon is fed by turning the tab.
Check the take-up operation. Be sure
the following parts operate with
operation of the carriage sub
assembly (1025)
Belt drive pulley (505)
Ribbon middle gear (512)
Ribbon drive plate sub assembly
(517)
Ribbon take-up gear sub assembly
(516)
Check the platen gap adjustment.
0.45 mm: falls with no weight applied
0.55 mm: does not fall
Checkpoints
Check the platen gap adjustment.
0.45 mm: falls with no weight applied
0.55 mm: does not fall
Checkpoints
Check the continuity with a tester. Make
sure no wires are broken or shorted out.
Check the continuity with a tester. Make
sure no wires are broken or shorted out.
Check the state of the dot wires. Make sure
they are not broken.
Action to correct the problem
Install the ribbon cassette correctly.
Completed if printing is normal.
Replace the ribbon cassette with a
new one. Completed if printing is
normal.
Replace the defective gear.
Completed if the operation is normal.
Adjust the platen gap (refer to page
5-5). Completed if printing is normal.
Action to correct the problem
Adjust the platen gap (refer to
page 5-5). Completed if printing
is normal.
Action to correct the problem
Replace the head FFC (521).
Completed if printing is normal.
Replace the print head unit
(503). Completed if printing is
normal.
Rev. B