Rockwell Automation 1772-LV,D17726.6.1 A and I MNL MINI-PLC-2/15 PROCESSO - Manual (Page 72)

Maintenance and Troubleshooting
Chapter 5
5Ć2
Generally, the sources of problems can be grouped into two board areas:
User’s hardware
Programmable Controller
The most likely source of a problem is the user’s hardware. This includes the
wiring, I/O devices, I/O power source and system power. Programmable
Controller faults can originate from the System Power Supply, Mini–PLC–2/15
Processor or the I/O Rack. Using the flowchart, and observing I/O device
behavior and Controller indicators, the user should be able to trace the source of
the problem to the user’s hardware or the Controller.
The following sections will deal with troubleshooting problems as they relate to
PC components. Observe all cautions and warnings as described in these
sections. One general warning should be observed throughout the
troubleshooting procedures:
WARNING: When cycling or removing line power, always use the
main disconnect switch. Never use the AC line fuse to cycle or
remove line power as contact with AC potentials may cause injury to
personnel.
In addition to the flowchart, the troubleshooting chart (Table 5.B) provides a
quick summary of corrective procedures according to Controller indicator
status.
The System Power Supply converts the incoming AC voltage to the proper DC
voltages to power the Processor and I/O Modules. The DC ON indicator
illuminates when the output voltages of the Power Supply are correct. If the DC
ON does not illuminate when AC power is applied, the possible fault sources
could be:
A blown Power Supply fuse
Incorrect position of jumpers on the terminal strip
Incorrect line voltage at Power Supply
Power Supply load of 6.5 amps is exceeded
Malfunctioning Power Supply
If the DC ON indicator illuminates but the RUN indicator is OFF when the
Controller is in the RUN or RUN/PROG mode, possible fault sources can
include:
AC line voltage out of range
Incorrect output voltages from Power Supply
Malfunctioning I/O Power Cable
Malfunctioning Processor
System Power Supply