Daktronics DF-1020 - Manual (Page 36)

Maintenance and
Troubleshooting
4-8
,” it is not receiving “signal in,” and is performing its own self-
test.)
+ Next, the first two digits of each line will display “Lx”, where “x” is the line
number that the driver is set to control (set with address plug).
+ Finally, each line will display “1234…” according to the column number of
each of its digits. Every line should show “1” on the left-most digit, and all
digits should be numbered consecutively from left to right. If this is not the
case, either the wrong address plug is installed, or the driver or digit harness
is connected incorrectly.
If there is no address plug in the host driver, the host driver will display “E5,” and
all client drivers will continually cycle through the power on self-test.
4.7 Lightning Protection
The use of a disconnect near the display to completely cut all current-carrying lines
significantly protects the circuits against lightning damage. The National Electrical
Code also requires it. In order for this device to provide protection, the power must
be disconnected when the display is not in use. The control console should also be
disconnected from power and from the signal j-box when the system is not being
used. The same surges that may damage the display's driver can also damage the
console's circuit.
4.8 Replacement Parts