Epson LX-300 Service Manual page 59

EPSON LX-300+
Table 3-3. Control Panel LED Does Not Light On.
Cause Check Point
Blowout of a fuse Is a fuse on the
on the power power board blew
board. out?
Are connectors
Connector is not
connected to the
connected to the
power board
power board.
properly?
Power switch is Is conductivity of
defective. the switch is OK?
Are +5VDC and
Power board is
+35VDC OK when
defective.
the power is on?
Power board and
the main board Is CN8 connected
are not connected properly?
properly.
Main board is
-
defective.
Control panel Is the harness of
harness is not the control panel
connected connected
properly. properly?
Control panel
board or harness -
is defective.
Troubleshooting
Y/N Solution
Check the electric circuit and
printer mechanism. If there is
YES
no short circuit, replace the
fuse.
NO Replace the power board.
YES Replace the power board.
NO Replace the power board.
NO Connect CN8 properly.
- Replace the main board.
Connect the harness
NO
properly.
- Replace the control panel.
Troubleshooting
Table 3-4. Printer Mechanism Does Not Operate.
Cause Check Point
Any of CN3 to
CN12 is not Are all connectors
connected to the connected
main board properly?
properly.
Main board is
-
defective.
Printer mechanism
-
is defective.
Table 3-5. When Power is Applied, the Printer Becomes Fatal Error.
Cause Check Point
Is CR motor
CR motor harness
harness CN10
is not connected
connected
properly.
properly?
CR motor is
-
defective.
HP detector Is HP detector
harness is not harness CN3
connected connected
properly properly?
HP detector is
-
defective.
Power board is Is power voltage
defective. normal?
- -
Revision A
Y/N Solution
NO Connect them properly.
- Replace the main board.
Replace the printer
-
mechanism.
Y/N Solution
NO Connect it properly.
- Replace the CR motor.
NO Connect it properly.
- Replace the HP detector.
NO Replace the power board.
Replace the main board and
-
printer mechanism.
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