Epson TM-U950 - Page 133

4-20 Troubleshooting Rev. A
Cutter blade operates
but full cut is not
performed or becomes
error.
Output signal failure B Check output signals at
contact pin holder sub
assembly with an
oscilloscope (blue: F/P
position pulse; red: reset
pulse; black: common).
Replace contact pin
holder sub assembly and
cutter slider assembly if
irregular chattering
(more than 2 ms pulse
width) is generated.
Remove any
contamination on
cutter slider assembly.
Paper dust or other
contamination has
accumulated on cutter
blade.
B Check for paper dust or
other contamination
Remove cover-cutter
blade receiving
assembly and remove
paper dust or other
contamination.
Cutter blade operates
but full cut is not
performed or becomes
error.
Gear wheel wear or
damage
B Check gear wheels for
wear and damage.
Replace gear wheels as
required.
Paper roll supplying
problem
A Check whether paper
roll corresponds to
specifications.
Use paper roll that
corresponds to
specifications.
A Check paper feed path. Repair paper feed
mechanism as required.
Slip paper is positioned
correctly, but printer
does not detect it.
Detector-slip paper
insertion sub assembly
failure
B Insert paper and check
detector output signal
with an oscilloscope.
Replace detector-slip
paper insertion sub
assembly.
Slip paper problem A Check whether slip
paper corresponds to
specifications.
Use slip paper that
corresponds to
specifications.
EEPROM (U20) failure B Check EEPROM (U20)
output signal.
Replace EEPROM (U20).
Slip paper eject waiting
status is not released
when slip paper is
removed.
Detector-slip paper
ejection sub assembly
failure
B Check detection signal
by using an oscilloscope
when slip paper is
removed.
Replace detector-slip
paper ejection sub
assembly.
Slip paper eject
detection circuit failure
B Check pin 70 of CPU
(U12) with an
oscilloscope.
Replace detector-slip
paper ejection
assembly.
Paper roll near-end
detection does not work
properly.
Microswitch failure A Check continuity
between microswitch
terminals and check on/
off operation.
Replace microswitch.
Slip paper is not
released.
Internal diameter of
paper roll core is too
small.
A Check internal diameter
of paper roll core.
Nominal value: 10 mm
(.39”) or more
Use paper roll that
corresponds to
specifications.
Table 4-3. Printer Mechanism Problems (continued)
Problem Probable Level Checkpoint Action
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