HP 330 Service Information Manual page 168

Troubleshooting Procedures
System Level
System level troubleshooting consists of finding out what part of a computer system is not
working correctly. A system consists of the computer and its installed accessories, interfaces,
peripherals, power source, and the users. Each of these system elements is subject to the
environment which includes, physical, electrical, and human factors.
When part or all of the computer system fails, your initial activity should be finding the part
of the system has the problem. One of the best things to do first is to talk to the users and ask
them to give specific. information on what they and the system were doing when the system, or
part of it, failed. You may have to duplicate their activities in order to make the failure occur.
If the failure is intermittent, this process may take some time.
Running tests on the system can also be helpful. A test is nothing more than a specific action
with the system that should result in a specific response. Simple tests are nothing more than
typing in simple instructions on the keyboard and executing them. A command to print or plot
specific date is an example. Mass storage, graphics, or other functions can be checked in the
same way. These type of tests are called Quick Checks.
After determining what part, or product, of the system is failing, the next step is to find out
what part of the product is causing the problem. In this case, it is assumed that the cOInputer
or expander has the problem. The rest of this chapter covers troubleshooting the computer and
expander.
Computer/Expander Troubleshooting
Both units may be analyzed alike, except for the processor in a computer's system slot. Each
has the same power supply, motherboard, fans, and backplane system.
Three levels of troubleshooting these products are explained. For each level different portions of
these products must be operational. A summary of these levels and what must be operational
is shown in Table 5-1.
In order to choose the best approach to start with, obtain as much information as possible from
the user. If the unit is not working at all, the Inoperative Unit Procedure is a good place to
start. If the user indicates that most of the unit is operating properly, the Functional Unit
Procedure may be a good place to start. If the users information is not conclusive, use the
following procedure to determine the problem area:
1. Turn the unit on and check for fan and Self-Test LED operation.
2. If the fans or LED's aren't working, go to the Inoperative Unit Procedure. If they do
work, go to the Functional Unit Procedure.
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Troubleshooting