User manual
Publication 1747-IN011F-EN-P - May 2007
Troubleshooting  145
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.










