4-2-2. Troubleshooting of 24VDC Power Supply. Fault isolation of the 24 VDC Power Supply to a defective
component(s) can be accomplished with the use of a Model 8840A/AF-05 Digital Multimeter (or equivalent) and
120 VAC, 60 Hz power source.
Based on the reported fault, follow the schematic diagram, checking for shorts, open circuits, or continuity using
The following table lists symptoms and probable cause(s) of the most likely faults.
Table 4-2. 24 VDC Power Supply Troubleshooting
Check R2, CR2, CR3.
AC IN LED does not illuminate, power output present at DC OUT
Check R1, CR1.
DC OUT LED does not illuminate, power output present at DC
OUT connector J2.
Circuit breaker trips when power applied. Ohmmeter checks
Indicate no shorts.
No power output at DC OUT connector, AC IN LED is illuminated.