Rockwell Automation 1772-LV,D17726.6.1 A and I MNL MINI-PLC-2/15 PROCESSO - Manual (Page 84)

Maintenance and Troubleshooting
Chapter 5
5Ć14
4. Remove the Processor from the I/O Chassis.
5. Remove the EPROM if installed in the Processor and install it in the
replacement Processor if necessary.
6. Install the replacement Processor in the I/O Chassis and turn the Mode
Select Switch to the PROG position.
7. Restore AC power and I/O power.
8. Load the User Program and verify proper operation.
If an EPROM is used, it will transfer its content into RAM memory when power
is restored. If the transfer was not successful, the MEMORY indicator will
illuminate. In this case, replace the EPROM with a blank one and load the User
Program into memory from magnetic tape.
Then program the EPROM after the User Program is verified.
The I/O Modules are powered by the 5.1V DC signal carried across the
backplane to the backplane connectors. The I/O devices connected to the
Module’s Field Wiring Arms are usually powered by an I/O power source.
If the output devices do not behave as programmed, yet the User Program is
correct and all diagnostic indicators imply normal operation, the source of the
fault could be:
Shorted wiring or open circuit to the output device
Blown Output Module fuse
I/O Module not correctly seated in Chassis
Malfunctioning Output Module
Wiring connected to wrong Field Wiring Arm terminal
Faulty I/O device
Faulty I/O power source
Follow the procedures as described in the troubleshooting flowchart to help
determine the source of the fault.
1771 I/O Modules