Replacing fuses program alteration – Rockwell Automation 1747-L5xx SLC 500 Modular Hardware Style User Manual User Manual
Page 143

Publication 1747-UM011G-EN-P - June 2008
Troubleshooting 143
Replacing Fuses
Program Alteration
There are several causes of alteration to the user program, including
extreme environmental conditions, Electromagnetic Interference
(EMI), improper grounding, improper wiring connections, and
unauthorized tampering. If you suspect the memory has been altered,
check the program against a previously saved program on an
EEPROM, UVPROM or Flash EPROM module.
Troubleshooting the
SLC 5/01 and SLC 5/02
Processors
Follow these steps to receive the maximum benefit of this
troubleshooting section.
1. Identify the status of your processor status indicators. See
chapter 5 for a description of status indicators and their states.
2. Using the tables on the following pages, match your processor
and power supply status indicators with the status indicators in
the first column.
3. Once the status indicators are matched to the appropriate table,
move across the table identifying error description and probable
causes.
4. Follow the recommended action steps for each probable cause
until the error is corrected.
5. If recommended actions do not correct the error, contact your
local Rockwell Automation sales office or distributor.
ATTENTION
When replacing a fuse, be sure to remove all power from the
system. Replacing a blown fuse can rarely restore power supply
operation, requiring the power supply to be replaced.