Repairing The Power Supply Board - Epson TM-FX2180 Service Manual

EPSON FX-2180 Service Manual
4. Abnormal Printing
START
Is the self test
YES
printed correctly?
NO
NO
Are all the
dots printed
correctly?
YES
Check the print head's
YES
Are all the
dots aligned
described in Table 3-1.
correctly?
NO
Perform the
B
bidirectional alignment.
(See Chapter 5.)
Check the platen Is the
NO
problem
gap/parallelism. (See
solved?
Chapter 5.)
YES
YES
END
YES
Is the
problem
solved?
END
NO
Are the bottoms of the
characters missing?
NO
YES
Replace the
print head.
Reinstall
the ribbon
mask.
END
NO
Is the
problem
solved?
YES
END
Figure 3-7. Flowchart 4
Check the data from the
host PC using the hex
dump mode.
Are the printer
YES
Are any print head
settings correct?
wires broken?
YES
NO
coil resistance as
Are the correct
printer drivers
installed?
YES
NO
Is the print head
coil resistance
correct?
Test the print
YES
head drivers on
the main board
Does the printer
Check the FFC
as described in
work correctly with
using a multimeter.
Table 3-7.
another printer
cable?
Replace the main
Is the FFC
board.
OK?
NO
END
Replace
Are the print
the FFC.
NO
head drivers on
the main board
OK?
NO
Replace the
Is the
print head
YES
problem
and the main
solved?
board.
YES
Replace the
print head. END
END
END

3.4 Repairing the Power Supply Board

The table below provides instructions on how to repair the power supply
board assembly. It lists various power supply board problems and
provides likely causes, checkpoints, and solutions. To determine whether
a component is defective, compare its readings with the correct
NO
Reset the settings
waveforms, resistances, and other values listed in the table below. Then
to their defaults.
replace the component if necessary.
YES
NO
Is the problem
solved?
WARNING
END
NO
Install the correct
printer drivers.
NO YES
Is the problem
solved?
END
YES
Note:
Replace the
NO
cable.
Use an oscilloscope to check the waveforms in Table 3-6.
Problem
YES
The +35 V and +5
Is the problem
solved?
V lines are not
NO
END
output when the
printer is turned
on.
The computer is the
source of the
problem.
The OPERATE button on the control panel only
turns the secondary power circuit on or off, so the
primary circuit is live as long as the printer is
connected to an AC power outlet. Before you
touch the power supply board or repair it,
disconnect the printer from the AC power outlet.
Table 3-6. Repairing the Power Supply Board
Cause
Diode bridge DB1 Measure the DC
is dead. voltage between pins
3 and 4 of DB1.
Transformer coil Measure the
T1 is open. resistances of the T1
transformer coils at
pins 12 and 15, 9 and
11, 7 and 8, and 3
and 4.
Chapter 3 Troubleshooting
Checkpoint Solution
Replace
DB1.
Replace
T1.
3-7