Chapter 5: Troubleshooting - HP 330 Service Information Manual

Troubleshooting
5
Introduction
Analytic Troubleshooting
Troubleshooting computers is the process of getting answers to these five questions:
• What exactly is wrong, or what are the bad symptoms?
• Where are the bad symptoms appearing?
• When do the bad symptoms occur?
• How bad is the problem or to what extent does it occur?
• What actually caused the problem in the first place?
Getting the answers to these questions usually makes the troubleshooting process much more
effective and less costly. When a failure in a computer system occurs, remember these questions
and get the answers to each of them.
After you have all answers possible, decide what's the most probable cause of the problem.
Sometimes you'll arrive at several choices for a cause. For each choice, qualify it against the
answers to the questions above. The most probable cause is the one that logically justifies the
correct answers to these questions.
Materials Required
Several items are required to troubleshoot the computer or expander to the failed assembly:
• Model 330/350 Computer and HP 98568 Opt. 132/98570A Expander Service Handbook
• Series 200/300 Test Tools Package.
• Digital Voltmeter.
• Anti-Static Workstation.
Test LED Displays
Eight test LEDs are located behind the front panel and are visible from the front of the computer.
In this manual, the LED's are shown in the following context:
LED On •
LED Off 0
Troubleshooting
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