SERVICING THE SCOREBOARD
While your scoreboard was designed for years of trouble-free operation, some problems may occasionally occur. Electro-Mech Scoreboard Company offers onsite service in some areas. In other areas, we can help you contact an independent service technician. In areas in which service is not available from Electro-Mech Scoreboard Company, we will make every effort to answer your questions. Our trained personnel at Electro-Mech Scoreboard Company are ready to answer your questions from Monday to Friday during the hours of 8 AM to 5 PM Eastern Standard Time. Be sure to know your scoreboard model number when calling. Scoreboard replacement parts are always available. Damaged parts can usually be repaired at a significant cost savings. Our convenient toll free number is listed at the bottom of every page in this manual.
TROUBLESHOOTING TIPS
Before calling Electro-Mech Scoreboard Co. for customer support of a scoreboard problem, it is helpful to make note of all the symptoms. If the scoreboard does not turn on LEDs, please check the following items:
- Make sure the control console power cord and the extension cable are plugged.
- Verify that the control console LCD display shows game information.
- Press control console keys and look for changes on the game information shown on the LCD display.
- Check the circuit breaker that supplies power to the scoreboard.
- Remove the upper scoreboard cabinet rear access panel cover and check the voltages present at Main Power terminal block.
- Check the fuses on the LPS5 and LPS7 Power Supply Modules.
- Make sure all wire and ribbon cable connections are plugged in securely.
- If the LEDs are now illuminated and the scoreboard reacts to control console entries, there may be a problem with the control cable or the ScoreLink 300 modem, if purchased.
If the scoreboard turns on LEDs, but does not operate normally, make note of which functions are affected. If some LEDs either never turn on or always stay on, make note of their specific locations on the scoreboard. Refer to the COMPONENT REPLACEMENT section of this manual before changing parts.
COMPONENT REPLACEMENT
LED digits and indicators are serviced from the front of the scoreboard.
LED Digits Replacement
The LEDs that form digits are soldered on circuit boards mounted behind metal masks. Do not attempt to replace individual LEDs. In case of a malfunction, the entire LED circuit board must be removed. To avoid damage to the LED driver module, always turn off the power to the scoreboard when removing or replacing LED digits. Figure 20 shows the components of an LED digit assembly. Possession indicators are similar in construction.

Figure 20 LED Digit Assembly
- The ribbon cable that connects to the rear of the circuit board is not designed to support the weight of the assembly.
- Damage to the ribbon cable may create short circuit paths that will damage the LDM12 LED driver module.
- Place the assembly on a flat surface and remove the 6-32 kep lock nuts that hold the circuit board in place.
- Remove the old circuit board.
- Align the mounting holes in the new circuit board with the threaded studs on the mask and install the replacement circuit board on the mask.
- Refer to Figure 21 in order to plug the ribbon cable IDC connector onto the circuit board in the proper orientation.

Figure 21 LED Digit Ribbon Cable Connection Diagram
LED Digit Driver - Large Boards are used when the current requirements of the scoreboard exceed the capacity of a LED Driver Module. These circuit board assemblies are mounted on standoffs behind LED digits, as needed. In case of a malfunction, the entire circuit board must be removed. To avoid damage to the scoreboard electronics, always turn off the power to the scoreboard when removing or replacing LED Digit Driver - Large Boards. Observe proper handling procedures to prevent static damage to these circuit boards. The table below lists the LED Digit Driver - Large Boards in this scoreboard and their functions.
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LED DIGIT DRIVER - LARGE BOARD
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FUNCTION #1
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FUNCTION #2
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CLOCK SECONDS UNITS DIGIT
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CLOCK SECONDS UNITS DIGIT
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CLOCK SECONDS TENS DIGIT
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CLOCK SECONDS TENS DIGIT
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CLOCK MINUTES UNITS DIGIT
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CLOCK MINUTES UNITS DIGIT
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CLOCK MINUTES TENS DIGIT
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CLOCK MINUTES TENS DIGIT
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HOME SCORE UNITS DIGIT
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HOME SCORE UNITS DIGIT
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HOME SCORE TENS DIGIT
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HOME SCORE TENS DIGIT
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HOME POSSESSION INDICATOR
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GUEST SCORE UNITS DIGIT
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GUEST SCORE UNITS DIGIT
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GUEST POSSESSION INDICATOR
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GUEST SCORE TENS DIGIT
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GUEST SCORE TENS DIGIT
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YARDS TO GO UNITS DIGIT
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YARDS TO GO UNITS DIGIT
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YARDS TO GO TENS DIGIT
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YARDS TO GO TENS DIGIT
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BALL ON UNITS DIGIT
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BALL ON UNITS DIGIT
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BALL ON TENS DIGIT
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BALL ON TENS DIGIT
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|
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QUARTER DIGIT
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QUARTER DIGIT
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|
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DOWN DIGIT
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DOWN DIGIT
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Figure 22 shows a LED Digit Driver – Large Board mounted behind a LED digit.

Figure 22 LED Digit Driver - Large Board LED Digit Driver - Large Board Replacement
- The wires and cables that connect to the rear of the LED digit and LED Digit Driver – Large Board are not designed to support the weight of the assembly.
- Damage to a ribbon cable may create short circuit paths that will damage the LDM12 LED driver module.
- Disconnect the wire assembly from the LED Digit Driver – Large Board J1 jack.
- Place the assembly on a flat surface and remove the 6-32 kep lock nuts that hold the LED Digit Driver – Large Board in place.
- Remove the old circuit board.
- Align the mounting holes in the new circuit board with the standoffs and install the replacement circuit board.
- Fasten the circuit board in place with the 6-32 kep lock nuts.
All other components are located behind the rear access panels. Figure 23 shows the view behind the upper access panel.

Figure 23 Upper Access Panel Components
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DRIVER MODULE
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JACK
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FUNCTION
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J1
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DRIVER MODULE DC POWER INPUT #1
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J2
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SERIAL DATA INPUT
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J3
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SERIAL DATA OUTPUT
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J4
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CLOCK SECONDS UNITS LED DIGIT DRIVER - LARGE BOARD J20
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J5
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CLOCK SECONDS TENS LED DIGIT DRIVER - LARGE BOARD J20
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J6
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CLOCK MINUTES UNITS LED DIGIT DRIVER - LARGE BOARD J20
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J7
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HOME SCORE UNITS LED DIGIT DRIVER - LARGE BOARD J20
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J8
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HOME SCORE TENS LED DIGIT DRIVER - LARGE BOARD J20
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J9
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GUEST SCORE UNITS LED DIGIT DRIVER - LARGE BOARD J20
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J13
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DRIVER MODULE DC POWER INPUT #2
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J14
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HORN RELAY CONTROL
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J17
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CLOCK MINUTES TENS LED DIGIT DRIVER - LARGE BOARD J20
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J20
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GUEST SCORE TENS LED DIGIT DRIVER - LARGE BOARD J20
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J21
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HOME TIME OUTS DIGIT
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J24
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GUEST TIME OUTS DIGIT
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Note: All other LDM12 jacks are unused.
LED Driver Module Replacement
Electrical connections to the LDM12 LED DRIVER MODULE are made with ribbon cable polarized IDC sockets and locking ramp crimp terminal housings that mate with jacks on the module. The module is secured inside the scoreboard with six machine screws.
- Do not cut the plastic tie wraps around the ribbon cables.
- Remove the six screws.
- Remove the module from the scoreboard.
- Insert the replacement module in the scoreboard.
- Secure the module with the six screws.
- Insert the plugs into the jacks on the module.
To avoid damage to the module, always turn off the power to the scoreboard when removing or replacing it.
LPS5 LED POWER SUPPLY MODULE FUNCTIONS
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JACK
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FUNCTION |
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J1
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120 VAC INPUT
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J2
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20 VDC OUTPUT TO LED POWER INTERFACE BOARD
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J3
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SERIAL DATA INPUT / OUTPUT
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J4
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HORN CONTROL
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J5
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SERIAL DATA TEST JACK
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A relay inside the LPS5 Power Supply Module isolates the LDM12 LED Driver Module from the control cable when the scoreboard is shut down. Connecting the control console to the test jack on the LPS5 Power Supply Module (J5) with the 10 ft. extension cable bypasses this relay. Figure 24 shows the location of the fuses in the LPS5 LED Power Supply Module. The table following the figure lists the fuse ratings, functions, and part numbers.

Figure 24 LPS5 Fuse Locations
LPS5 FUSES
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FUSE
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RATING
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FUNCTION
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BUSSMAN PART #
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F1
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3A 250V
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TRANSFORMER PRIMARY
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AGC-3
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F2
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5A 250V
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LED POWER INTERFACE BOARD J1
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AGC-5
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F3
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5A 250V
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LED POWER INTERFACE BOARD J6
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AGC-5
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F4
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½A 250V
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SERIAL DATA ISOLATION RELAY
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AGC-1/2
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F5
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1A 250V
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HORN
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AGC-1
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F6
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½A 250V
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120 VAC ELECTRICAL RECEPTACLE
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AGC-1/2
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Note: Other manufacturers’ fuses may be substituted for the Bussmann fuses.
LPS7 LED POWER SUPPLY MODULE FUNCTIONS
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JACK
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FUNCTION
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J1
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120 VAC INPUT
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J2
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20 VDC OUTPUT TO LED POWER INTERFACE BOARD
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Figure 25 shows the location of the fuses in the LPS7 LED Power Supply Module. The table following the figure lists the fuse ratings, functions, and part numbers.

Figure 25 LPS7 Fuse Locations
LPS7 FUSES
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FUSE
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RATING
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FUNCTION
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BUSSMAN PART #
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F1
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3A 250V
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TRANSFORMER PRIMARY
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AGC-3
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F2
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5A 250V
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LED POWER INTERFACE BOARD J11
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AGC-5
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F3
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5A 250V
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LED POWER INTERFACE BOARD J16
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AGC-5
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Note: Other manufacturers’ fuses may be substituted for the Bussmann fuses.
LED Power Supply Module Replacement
Electrical connections to the LED Power Supply Modules are made with keyed plugs that mate with jacks on the left side of the module. The modules are secured inside the scoreboard with four machine screws each.
- Disconnect the plugs from the jacks on the side of the module.
- Remove the four screws.
- Remove the module from the scoreboard.
- Insert the replacement module in the scoreboard.
- Secure the module with the four screws.
- Insert the plugs into the jacks on the side of the module.
To avoid damage to the module, always turn off the power to the scoreboard when removing or replacing it.
The LED Power Interface board distributes the output from the power supply modules to the LDM12 LED driver module and the LED digit driver – large board assemblies.
LED Power Interface Board Replacement
- Unplug the wire assemblies from the jacks on the circuit board.
- Unseat the circuit board from the standoffs.
- Press the replacement circuit board in place on the standoffs.
- Each wire assembly is labeled to indicate the correct jack connection.
Surge Suppressor Replacement
Electrical connections to the Surge Suppressor are made with ¼” quick disconnects that mate with ¼” tabs on the top of the module. The module is secured inside the scoreboard with one machine screw.
- Unplug the electrical connections from the module.
- Remove the screw.
- Remove the module from the scoreboard.
- Insert the replacement module in the scoreboard.
- Secure the module with the screw.
- Figure 26 shows the top view of the Surge Suppressor.

Figure 26 Surge Suppressor Terminals
Figure 27 shows the view behind the lower access panel.

Figure 27 Lower Access Panel Components
LDM12 LED DRIVER MODULE FUNCTIONS
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|
|
|
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DRIVER MODULE
|
|
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JACK
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FUNCTION
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J1
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DRIVER MODULE DC POWER INPUT #1
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J2
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SERIAL DATA INPUT
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J3
|
SERIAL DATA OUTPUT
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J10
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YARDS TO GO UNITS LED DIGIT DRIVER - LARGE BOARD J20
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J11
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YARDS TO GO TENS LED DIGIT DRIVER - LARGE BOARD J20
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J12
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BALL ON UNITS LED DIGIT DRIVER - LARGE BOARD J20
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J13
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DRIVER MODULE DC POWER INPUT #2
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J16
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QUARTER LED DIGIT DRIVER - LARGE BOARD J20
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J22
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DOWN LED DIGIT DRIVER - LARGE BOARD J20
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J23
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BALL ON TENS LED DIGIT DRIVER - LARGE BOARD J20
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Note: All other LDM12 jacks are unused.
LPS6 LED POWER SUPPLY MODULE FUNCTIONS
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JACK
|
FUNCTION
|
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J1
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120 VAC INPUT
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J2
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20 VDC OUTPUT TO LED POWER INTERFACE BOARD
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J3
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SERIAL DATA INPUT / OUTPUT
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J4
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12 VDC RELAY FUNCTIONS (NOT USED ON THIS SCOREBOARD)
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J5
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SERIAL DATA TEST JACK
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Connecting the control console to LPS6 test jack (J5) with the 10 ft. extension cable enables the operation of the lower section of the scoreboard from the lower access panel. Disconnect the cable wires that are connected to the bottom of the terminal block labeled Data from Top Section. Figure 28 shows the location of the fuses in the LPS6 LED Power Supply Module. The table following the figure lists the fuse ratings, functions, and part numbers.

Figure 28 LPS6 Fuse Locations
LPS6 FUSES
|
FUSE
|
RATING
|
FUNCTION
|
BUSSMAN PART #
|
|
F1
|
3A 250V
|
TRANSFORMER PRIMARY
|
AGC-3
|
|
F2
|
5A 250V
|
LED POWER INTERFACE BOARD J1
|
AGC-5
|
|
F3
|
5A 250V
|
LED POWER INTERFACE BOARD J6
|
AGC-5
|
|
F4
|
1A 250V
|
12 VDC RELAY OUTPUT (NOT USED ON THIS SCOREBOARD)
|
AGC-1
|
|
F5
|
1A 250V
|
12 VDC RELAY OUTPUT (NOT USED ON THIS SCOREBOARD)
|
AGC-1
|
|
F6
|
½A 250V
|
120 VAC ELECTRICAL RECEPTACLE
|
AGC-1/2
|
Note: Other manufacturers’ fuses may be substituted for the Bussmann fuses.