Epson Stylus Color 760, Service Manual

Page: 68 / 172

EPSON Stylus COLOR 760 Revision C
Troubleshooting Overview 68
Table 3-13. CR Motor does not Operate Table 3-14. PF Motor does not Operate
Step Check Point Action
1 Getting ready
for inspecting
waveforms.
The connector CN14 used to control the CR motor is
indicated in the figure below. Using the oscillo scope,
check for the waveform for each phase at the indicated
connector.
To check the waveform, press the Load/Eject button to
attempt to move the carriage. Be sure to leave the cable
for the CR motor connected.
NOTE: The GND can be output by placing the probe of
the oscillo scope to the tapped hole in the
bottom plate on the board with a screw. Note
the connector has no ground line since this
printer drives the motor with the bipolar system.
2 Check of the
waveform and
remedies While trying to drive the CR motor, the waveform output
from each phase should be as shown in the figure. If the
waveform output from each phase is as shown below,
replace the CR motor. If not, replace the IC18 (CR motor
driver IC) or C298 Main Board.
NOTE: The GND can be output by placing the probe of
the oscillo scope to the tapped hole in the
bottom plate on the board with a screw.
C298Main Board
5 0 V 5 0 V
S A M P L E C 2 0 u S
V 1 = 0 . 1 V
B l a c k L i n e : C R - A
R e d L i n e : C R - B
Step Check Point Action
1 Getting ready
for inspecting
waveforms.
The CN13 connector used to control the PF motor is
indicated in the figure below. Using the oscillo scope,
check for the waveform for each phase output from the
indicated connector. To check the waveform, press the
Load/Eject button to attempt the ASF paper feeding. Be
sure to leave the cable for the PF motor connected.
NOTE: The GND can be output by placing the probe of
the oscillo scope to the tapped hole in the
bottom plate on the board with a screw. Note
the connector has no ground line since this
printer drives the motor with the bipolar system.
2 Check of the
waveform and
remedies. While trying to drive the PF motor, the waveform output
from each phase should be as shown in the figure. If the
waveform output from each phase is as shown in the
figure, replace the PF motor. If not, replace the IC19 (PF
motor driver IC) or C298 Main Board.
NOTE: The GND can be output by placing the probe of
the oscillo scope to the tapped hole in the
bottom plate on the board with a screw.
C298Main Board
5 0 V 5 0 V
S A M P L E C 2 0 u S
V 1 = 0 . 1 V
B l a c k L i n e : P F - A
R e d L i n e : P F - B