Rockwell Automation 2706-F11J_F11JC_F21J_F21JC DL50 INSTALLATION MANUAL - Manual (Page 101)

Chapter 8
Troubleshooting and Maintenance
8–6
3. Observe the diagnostic LEDs (Figure 8.1). If both the AC and DC
indicators are on, then the display should be cycling through diagnostic
tests. During the display test, the DL50 will display patterns of scrolling
both horizontally and vertically. Inspect each display board for faulty
LEDs (continuously in an ON or OFF state).
•
If faulty LEDs are detected, the display board needs to be replaced.
Refer to Replacement Parts List in this chapter.
•
If nothing is displayed, then either the connection from the processor
board to the display board is faulty or the processor board is faulty.
Check connections. Check the output of the processor board by
connecting a dumb terminal to the RS-232 port. If no text is displayed
on the dumb terminal screen, the processor board needs to be replaced.
Refer to Replacement Parts List, Table 8.B.
4. If the AC LED is On and the DC LED(s) are Off, check the AC power
fuse. (See Figure 8.2 for the location of this fuse.) If the fuse is ok and
there is power at the AC input of the power supply, then either the LED
on the processor board or the power supply is faulty. Use a voltmeter to
verify the presence of +5V DC on the output of the power supply(s). If
+5V DC is not present, the power supply is faulty. If +5V DC is present,
the processor board is faulty. Refer to Replacement Parts List, Table 8.B.
5. If the AC LED is Off, there is either an incorrect supply voltage or a
defective power supply. Measure the voltage at the AC input terminal. If
the proper AC voltage is present and the fuse is good (see Figure 8.2 for
the location of this fuse), the power supply is defective. Refer to
Replacement Parts List, Table 8.B.