Epson Perfection 1200U Service Manual page 29

EPSON Perfection1200
Table 3-5. Carriage Unit does not operate
Cause Step Checkpoint
Power 1 With the scanner power on,
board is check the voltage output level
broken. between the Pins 4/5(+) and
Pins 6/7 (-) for CN101 on the
power board. Is it +24VDC?
Carriage 2
Is grease (G-26) applied
Unit (or CR
correctly?
move
mechanism)
3 • With power ON and the
is broken.
scanner upper case
removed, does CR motor
move?
• With the CR motor
removed, does the
carriage unit move
smoothly?
CR Motor is 4 Disconnect the connector
broken CN5 on the main board, then
use the tester and check the
coil resistance between Pin2
and 4 and between Pin1 and
3. Is the resistance of 2 points
Ω?
about 6.2
5 If any motor coil is shorted,
check the CR motor drive
circuit in the order below.
1.)Set the tester on Ohms.
2.)Place the (-) lead of the
tester on any of Pins 1,2, 3 or
4 of CN5 on the main board.
3.)Place the (+) lead of the
tester on Pin 6/7 of CN6 (*1)
on the main board.
With the scanner off, does the
∞
meter show "
Main board 6
is broken.
Troubleshooting
Finding Solution
No Replace the power
board.
No Apply the grease to
the appointed
position. (See Ch6)
No Check the carriage
move mechanism
and replace the
corresponding parts
or disassemble and
assemble the part.
No Replace the CR
motor.
No Replace the main
board.
"?
--- --- Replace the main
board.
NOTE: *1: This connector number is for SCSI. The connector number for
USB is CN3.
Table 3-6. Carriage moves but an error is indicated
Cause
CR home position
sensor is broken.
Table 3-7. Lamp does not light up
Cause
Connector CN4 on
the control board is
disconnected.
Connector CN1 or
CN2 on the CCD
board disconnected.
Lamp is not
connected properly
to the connector on
the inverter board.
Lamp is broken.
Inverter board is
broken.
Main board is
broken.
Troubleshooting
Step Checkpoint Finding
1 Check the signal --
level.
• Check the
signal/status
level between
C(+) and E(-) of
PC1.
H (about 4.5V)/
when C-E of PC1 is
closed.
L (0.3V)/when C-E
of PC1 is opened.
Step Checkpoint Finding
1 Is the connector CN4 Yes
on the control board
disconnected?
2 Is the connector CN1 Yes
or CN2 on the CCD
board disconnected?
3 Is the lamp connected No
properly to the
connector on the
inverter board?
4 Does the lamp light Yes
after it is replaced?
5 Does it operate Yes
properly after
replacing it?
6 --- ---
Revision B
Solution
Replace the CR
home position
sensor (PC1) on
the main board.
Solution
Connect CN4
properly.
Connect CN1 or 2
properly.
Connect the lamp
properly.
Replace the
lamp.
Replace the
inverter board.
Replace the main
board.
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