Maintenance and Troubleshooting
19
Troubleshooting
For additional assistance, contact Daktronics Transportation Customer Service at the
telephone number on the cover page.
Problem Observed
Possible Cause
Solution
No LEDs light, and the
Vanguard
®
Field Controller
does not communicate with
the central controller.
No power.
Check that the traffic cabinet
has power.
Vanguard
®
Field Controller or
modem is bad.
Refer to the controller manual.
No LEDs light, but the
Vanguard
®
Field Controller
communicates with the central
controller. All peripherals
indicate Communication Error.
No power at the display.
Check that the circuit breakers
in the traffic cabinet are on
and not tripped.
Vanguard
®
Field Controller is
bad or is not connected to the
display.
Refer to the controller manual.
VCB is bad.
Replace VCB.
No LEDs light, but the
peripherals pass and the
Vanguard
®
Field Controller
is communicating with the
central controller.
VCB is bad.
Replace VCB.
No power to power supply
groups.
Check that the circuit breakers
are on and are not tripped.
LEDs on the entire display are
garbled, or wrong LEDs are on
throughout the display.
Signal connections at the VCB
are incorrect.
Check the signal wiring.
Vanguard
®
Field Controller is
bad.
Refer to the controller manual.
Vanguard
®
Field Controller
has the wrong display
configuration.
Refer to the controller manual.
One line of modules does not
respond properly. LEDs are
garbled, do not change, are
too bright or too dim, etc.
One or more wires or terminals
in the signal cable (for this line)
is misplaced, open or shorted
to wires or frame, in display,
Vanguard
®
Field Controller, or
control cable from display to
Vanguard
®
Field Controller.
Repair wires as needed.
Terminating resistor on the CAN
bus for this line is bad.
Replace the terminating
resistor.
One or more drivers in this line
are bad.
Replace modules in the line
one at a time and retest each
time.
Note:
There may be more
than one bad driver. Repair
the failed driver.
VCB is bad.
Replace VCB.
