3-1
This chapter presents 4020 problems experienced in the field and those analyzed
by Service Repair. This information is arranged in three categories:
•
General Issues
•
Problems Associated with Assembly / Dis-Assembly and Installation
•
Problems Associated with Power Supplies
Service Repair data indicates that system problems are most likely to reside in
the Standard Slave PCB assembly followed by the Power I/O Interface card.
Based upon Service Repair records, the estimated distribution of 4020 system
PCB failures is:
41%
Standard Slave
33%
Power I/O Interface
15%
Master Controller
11%
Universal Switcher Power Supply
Most Standard Slave problems appear to occur during the system installation
phase or during upgrades. Many system problems appear to result from
improper system wiring during installation or system upgrade.
Because of the individual sub-assembly interaction, what may appear to be a
power supply problem may, in fact, be caused by a problem on either the
Standard Slave or Power I/O Interface assembly.
A great deal of system complexity has been concentrated on the Standard Slave
Assembly and a considerable amount of interaction between assemblies is
required for proper system initialization and operation. Again, because of sub-
assembly interaction, what may appear to be a power supply problem may, in
fact, be caused by a problem on either the Standard Slave or Power I/O Interface
assembly.
Chapter 3
4020 Problem Experience
Overview
Where Problems are likely to
Reside
Troubleshooting Difficulty
