Service manual

4. Abnormal Printing
START
END
Is the
selftest excecuted
correctly ?
Are all
YES
YES
YES
YES
YES
NO
NO
the dosts printed
OK?
Are any
wires in the
printhead
broken?
NO
Do all
the LEDs on
the control panel
blink at power on?
Check printhead, motors
drivers and power supply
with a meter.
Replace any bad parts.
Is the
problem
corrected ?
END
Is the
FFC
connected
correctly?
Connect the
cable correctly.
Is the
problem
corrected ?
Check
the FFC using a
multimeter. Is it
OK?
Replace the
FFC.
Is the
problem
corrected ?
END
END
END
END
ENDReplace the C186
MAIN baord.
ENDEND
END
Replace the
printhead..
Is the
problem
corrected ?
Check
the FFC using
a multimeter.
Is it OK ?
NO
YES
YES
NO
NO
NO
NO
YES
YES
NO
YES
NO
YES
YES
Replace the C186
MAIN baord.
ENDEND
END
END
END
Replace the
FFC.
Is the
problem
corrected ?
NO
NO
YES
END
END
Reinstall the
Ribbon mask.
Is the
problem
corrected ?
NO
YES
END
END
NO
YES
NO
Date received from the
host is not printed
correctly.
Are
printer
settings
correct?
YES
Are
the correct
printer drivers
installed ?
Reset the
printer.
NO
YES
Is the
probelm
corrected?
END
YES
NO
Install the correct
printer driver.
Is the
probelm
corrected?
Dose
the printer
work OK with
another
computer?
NO
YES
YES
Replace the C186
MAIN abord
END
Problem with
computer.
END
END
NO
YES
Dose
the resistence
of printhead wires
check OK?
YES
Is the
bottom of
characters
missing ?
Figure 5-6 Flowchart 4
LQ-2070 Service Manual Troubleshooting
Rev.A 5-9