Recover From Fatal Errors; Troubleshoot The 8720Mc-Rps Unit; Preliminary System Checks - Allen-Bradley 8720MC-RPS065 User Manual

Recover From Fatal Errors

Error Code Error Description
SCx Self Check Error
CHS Checksum Error
CPU CPU Error
SYS System Error
Troubleshoot the
8720MC-RPS Unit
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
Error Cause
Error was detected during self-diagnostics. 'x' in
the error code represents an integer value of
1...7.
Writing parameter value to EEPROM was not
successful.
Unexpected error occurred during CPU internal
calculation.
Unexpected error occurred.
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
Rockwell Automation Publication 8720MC-RM001K-EN-P - September 2018

Troubleshoot the 8720MC-RPS Unit

Corrective Action
Contact your local Rockwell Automation sales representative or replace the
Regulator Board.
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.
Contact your local Rockwell Automation sales representative or replace the
Regulator Board.
Contact your local Rockwell Automation sales representative or replace the
Regulator Board.
Chapter 8
105