Phaser 4400 Laser Printer Service Manual
3-1
Troubleshooting
Introduction
This section covers two types of troubleshooting procedures:
■
Troubleshooting procedures for problems not directly associated with error
messages or codes
■
Troubleshooting Procedures for Image-quality (IQ) problems
Troubleshooting procedures will normally isolate a problem to a specific component
or subassembly, in some cases including the wire harnesses.
In the Yes/No steps of the procedures, a Yes/No response will either lead you to the
next step or will indicate a corrective action. When you complete the indicated
corrective action, restart the System Check to verify that the problem has been
corrected.
Measurements
Power and signal grounds are connected to frame ground. You can perform all circuit
troubleshooting using the metal frame (chassis) as the grounding point. If you need
more information to locate connectors or test points, refer to
Wiring Data
on page 9-1.
Unless otherwise specified, the following voltage tolerances are used within this
section:
Section Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Index of Troubleshooting Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Image-Quality Checkout Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-41
Index of Image-Quality Checkout Procedures . . . . . . . . . . . . . . . . . . . . . . . . 3-41
Image-Quality Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . .3-53
Index of Image-Quality Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . 3-53
Voltage Measurements
Stated
Measured
Stated
Measured
+3.3 VDC
+3.0 to 3.6 VDC
+24.0 VDC +21.6 to +26.4 VDC
+5.0 VDC
+4.8 to +5.2 VDC
0.0 VDC
Less than +0.5 VDC
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