Rockwell Automation 1762-Lxxxx MicroLogix 1200 Programmable Controllers - Manual (Page 122)

Publication 1762-UM001G-EN-P - March 2011
C-2 Troubleshoot Your System
Normal Operation
The POWER and RUN LEDs are on. If a force condition is active, the
FORCE LED turns on and remains on until all forces are removed.
Error Conditions
If an error exists within the controller, the controller LEDs operate as
described in the following table.
If the
LEDS
indicate The Following Error
Exists Probable Cause Recommended Action
All LEDs off No input power or
power supply error
No line Power Verify proper line voltage and connections to the controller.
Power Supply
Overloaded This problem can occur intermittently if power supply is overloaded when
output loading and temperature varies.
Power and
FAULT
LEDs on
solid Hardware faulted Processor Hardware
Error Cycle power. Contact your local Allen-Bradley representative if the error
persists.
Loose Wiring Verify connections to the controller.
Power LED
on and
FAULT LED
flashing Application fault Hardware/Software
Major Fault Detected For error codes and Status File information, see MicroLogix 1200 and 1500
Programmable Controllers Instruction Set Reference Manual, Publication
1762-RM001.
RUN
FORCE
FAULT
LEDs all
flashing
Operating system
fault Missing or Corrupt
Operating System See Missing/Corrupt OS LED Pattern on page D-2.