Daktronics CH-1436H - Manual (Page 20)

Maintenance &
Troubleshooting
3-2
Reference Drawing: Segments, 4x7 Lamp Matrix Digit.................. Drawing A-37685
In a digit certain lamp always go on and off together. These groupings of lamps are known as
"segments". Each digit has eight segments, referred by letters A through H. Drawing A-
37685 illustrates these segments and shows which connector pin and wire color is wired to
each segment.
3.4 Schematic
Reference Drawings: Schematic, Pwr & Sig, CH-1436H ............... Drawing A-63789
Component Locations, CH-1436H .............. Drawing A-63922
Power & Signal Entrance, CH-1436H ......... Drawing A-63923
The schematic diagram in Drawing A-63789 shows the power and signal inputs into the
display and to the lamp driver. The component numbers correspond to those shown in
Drawings A-63922 and A-63923.
3.5 Troubleshooting
Observed Problem Possible Cause
One lamp won’t light
• Burned-out lamp
• Broken wire behind digit
Digit segment won’t light
• Broken wire
• Poor contact at driver connector
• Internal driver malfunction
Entire digit won’t light
• Broken wire (black)
• Poor contact at connector, pin 7
• Fuse blown in driver
Half the display won’t light • Service breaker tripped
• Main fuse blown
• Poor contact at main power connection
• P18 disconnected
Entire display won’t light • Power disruptions
• Poor signal connection
• Driver logic fuse blown
• Control not connected to display
• P20 disconnected
Segment stays lit • Broken wire behind digit
• Internal driver malfunction
Garbled display • Control malfunction
• Internal driver malfunction
If a problem is observed in one digit, the cause may be isolated by swapping plugs on the
driver (connect the plug from the digit into a different jack). If the same digit shows the same
problem, the cause may be in the digit or the wiring. If the problem moves to another digit,
then the cause is probably an internal driver problem.
Use a volt meter at driver inputs to determine if power is being supplied to the driver. An
ohmmeter can be helpful in finding broken wires and bad connections. Internal electronic
problems must be corrected by Daktronics or an authorized service center.