Section 3 : Maintenance & Troubleshooting
Maintenance & Troubleshooting
3-1
IMPORTANT NOTES:
1. Disconnect power before any repair or maintenance work is done on the
display!
2. Any access to internal display electronics must be made by qualified
service personnel.
3. Disconnect power when the display is not in use.
3.1 Lamp
Replacement
Reference Drawing:
Digit Service ..................................................
The primary service required by the CH-1421V display is to replace burned-out lamps. Refer
to
Drawing A-27674
for an illustration of lamp changing. Digit lamps are 25W, 120 volt,
Daktronics part number DS-1029. Some displays may be equipped with 30W, 120 volt digit
lamps, Daktronics part number DS-1126. Lamps may be bought at your local store or directly
from Daktronics.
Do not use lamps larger than those originally installed in the display. Using higher powered
lamps will likely cause fuse failures in the display and could exceed the current levels that the
display’s circuits can safely handle.
3.2 Lamp
Driver
Reference Drawings:
Lamp Driver, 16 Col., w/ Fan.......................
Component Numbering,CH-1421V ...........
In the display, the task of switching lamps on and off is performed by the lamp driver.
Drawing A-106020
in
Section 2
shows the location of the lamp driver in the display.
Drawing A-37070
is an illustration of the lamp driver and the fuses located in it.
The lamp driver has 21 connectors, providing power and signal inputs and outputs to digits.
The functions of these connectors are as follows:
Connector Number
Function
1-16
Outputs to digits
17 Signal
Input
18
Power input for outputs 1-8 (120 V)
19
Power input for driver logic and fan (120V)
20
Power input for outputs 9-16 (120V)
24
Dim option selector
In
Drawing A-106020
, the numbers on the digits refer to the lamp driver output connector
wired to each digit.
