Page: 113
Service Guide ML520/521
Chapter 4 Failure & Repair Analysis
4.1.01 Introduction
This section is used to isolate problems to the assembly level. Application problems and detection of
faulty components on the printed circuit boards are NOT addressed.
When troubleshooting a defective unit, follow these steps.
1. Refer to Section 4.3, which explains where to check for updates to the troubleshooting information.
2. Section 4.4 contains tips on preventing problems, as well as a list of common problems.
3. Section 4.5 shows samples of abnormal outputs.
4. Section 4.6 provides tables of error messages.
5. Section 4.7 contains the Repair Analysis Procedures (RAPs). Each RAP will ask you questions or
require you to make observations. The answers to these questions and the results of your
observations determine your next course of action. Use the RAP Index to identify which RAP should
be used to resolve the problem with the machine.
6. Section 4.8 provides the procedures for various printer tests.
7. Section 4.9 lists the resistance check points.
8. Section 4.2 lists methods for reporting problems. If you encounter a situation that is NOT addressed
by the documentation in this kit, please report the problem to Okidata, using one of the methods listed.
Refer to the Service Center Reference Guide for information on contacting Okidata.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
