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Service Guide ML520/521
Chapter 4 Failure & Repair Analysis
4.4.02 Problem Categories
There are three categories of problems that you might encounter when servicing the printer.
ALARM Lamp Blinks (Fatal Errors)
The following can cause the ALARM lamp to blink.
Open Bail Arm
Jammed Paper
Printhead Cannot Move
Other Fatal Error
When the ALARM Lamp is blinking, check the items listed below.
1. Close the bail arm.
2. Check for a paper jam.
3. Verify that the printhead moves freely.
4. Record the status of the ALARM, PRINT QUALITY, and CHARACTER PITCH Lamps.
5. Refer to the Alarm Lamp Codes Table. (Section 4.6)
6. Locate the error.
7. Perform the designated corrective action.
Operational Errors
An Operational Error is usually not accompanied by an ALARM Lamp.
Refer to the Start Here Flowchart (Section 4.4.03) and perform the corrective action.
ALARM Lamp Lights (Paper End/Jam Conditions)
A solid ALARM Lamp usually indicates a cover open, paper jam or paper-end (out of paper) condition.
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