Service manual

EPSON Stylus Photo 870/1270 Revision B

TROUBLESHOOTING Overview 69

3.1.3 Isolating the Faulty Part according to the Phenomenon

Refer to this section if you could not solve the problem in Section 3.1.1.1

or Section 3.1.2 or need more information to isolate the cause according

to the exhibited phenomenon. This section mostly covers the problems

relating to the main control circuit and other parts.

Table 3-11. Phenomenons Exhibited

No. Phenomenon Exhibited Table to refer to

1 CR motor does not rotate. Table 3-12

2 PF motor does not rotate. Table 3-13

3 Pump/ASF motor does not rotate. Table 3-14

4 Cleaning does not solve the print

problem.

Table 3-15

Table 3-12. CR Motor does not Work

Step Checkpoint

Action

1 Getting ready

for checking

waveforms.

Using an oscilloscope, check the outputwaveform at

CN14 (CR motor connector) on the main board. For

checking, press the Load/Eject button to drive the CR

motor.

NOTE:

Be sure to disconnect the CR motor cable.

NOTE:

Ground one of the probes to the frame. The

connector itself has no ground line since the

CR motor is a bi-polar motor.

2 Checking the

waveforms to

solve the

problem.

Drive the CR motor and check that the waveform

shown below is output from each pin of CN14.

• If the waveform appears as shown, replace the CR

motor.

• If not, replace the main control board or the CR

motor driver IC (IC18).

20V