
Rockwell Automation Publication 8720MC-RM001K-EN-P - September 2018
105
Troubleshoot the 8720MC-RPS Unit
Chapter 8
Recover From Fatal Errors
Fatal error codes generally indicate a malfunction of the regulator board. If
cycling input power does not remove the error, replace the 8720MC-RPS unit.
Table 34 - Fatal Error Codes
Troubleshoot the
8720MC-RPS Unit
Follow these preliminary system checks and flow charts to track the
8720MC-RPS unit powerup sequencing.
Preliminary System Checks
Follow these steps to verify that the 8720MC-RPS unit was installed correctly.
1.
Turn OFF input power to the 8720MC-RPS unit and wait until
POWER status indicator is OFF.
2.
Verify that the DC-bus voltage is zero and that the DC-bus capacitors
are completely discharged.
3.
Make the following checks:
• Connectors not seated properly
• Loose wire terminations to connectors
• Input power voltage within tolerance
• Verify that all sources of electrical noise (relays, solenoid-valves, and
magnetic brakes, for example) are provided with surge suppressors.
• Installation instructions were followed correctly
Error Code
Error Description
Error Cause
Corrective Action
SCx
Self Check Error
Error was detected during self-diagnostics. ‘x’ in
the error code represents an integer value of
1…7.
Contact your local Rockwell Automation sales representative or replace the
Regulator Board.
CHS
Checksum Error
Writing parameter value to EEPROM was not
successful.
Set again the Unit Selection (F.001), and restore all the parameters to the
default values.
If this error occurs intermittently, contact your local Rockwell Automation sales
representative or replace the Regulator Board.
CPU
CPU Error
Unexpected error occurred during CPU internal
calculation.
Contact your local Rockwell Automation sales representative or replace the
Regulator Board.
SYS
System Error
Unexpected error occurred.
Contact your local Rockwell Automation sales representative or replace the
Regulator Board.