Overview - Epson Stylus Photo 750 Service Manual

EPSON Stylus Photo 750

3.1 Overview

This section describes how to identify and troubleshoot the problems
when repairing the printer by dividing the troubles into two levels; repair
and replacement of the assemblies and units, and repair of the
components. Refer to the flowchart below and perform repairing the
component after separating the defective units.
Figure 3-1. Troubleshooting Flowchart
Table 3-1. Motor, Coil Resistance
Motor Location
CR Motor CN7
PF Motor CN8
Troubleshooting
Check Point Resistance
Pin 1 and 3
7.8 Ohms 10% (at
25 C/one phase)
Pin 2 and 4
Pin 1 and 3
8.8 Ohms 10%
(at 25 C/one phase)
Pin 2 and 4
Table 3-2. Sensor Check Point
Sensor Name Check Point
HP Sensor CN4/Pin 1 and 2
PE Sensor CN5/Pin 1 and 2
ASF Sensor CN6/ Pin 1 and 2
Thermistor
Head side CN9/
Pin 3 and 4
(THM)
Black cartridge Head side CN9/
sensor (COB) Pin 1 and 4
Color cartridge Head side CN9/
sensor (COC) Pin 2 and 4
Overview
Revision A
Signal Level Switch Mode
Open (Out of HP
Less than 0.7V
range)
Close (Within HP
More than 2.4V
range)
Open (Paper
Less than 0.7V
exists)
More than 2.4V Close (No paper)
Open (Paper Feed
Less than 0.7V Roller home
position)
Close (Out of home
More than 2.4V
position)
Analog signal 10 K (at 24 C)
Open (Cartridge is installed)
Close (No Cartridge)
Open (Cartridge is installed)
Close (No Cartridge)
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