Pc Board Status Lights - Lincoln LT-7 Troubleshooting Manual

B-21

PC BOARD STATUS LIGHTS

Table B.1 is a summary of the on/off states of the LED's on the Control Board, Logic Board and
Voltage Board for various conditions of the LT-7. Table B.2 lists the functions that these LED's indi-
cate.
INDICATOR LIGHTS CONDITIONS FOR LIGHT "ON"
LIGHT LOCATION IDLE
NO. MODE
1A CONTR. BD.
1B CONTR. BD.
1C CONTR. BD.
1D CONTR. BD. ON
1E CONTR. BD.
2B LOGIC BD.
2C LOGIC BD.
2D LOGIC BD. ON*
2E LOGIC BD.
2F LOGIC BD. ON
2H LOGIC BD.
2J LOGIC BD.
2K LOGIC BD.
2L LOGIC BD.
2M LOGIC BD.
3A VOLT BD.
3B VOLT BD.
ON* INDICATES LIGHT IS DIM
LIGHT NUMBER
1A
1B
1C
1D
1E
2B
2C
2D
2E
2F
2H
2J
2K
2L
2M
3A
3B
TROUBLESHOOTING AND REPAIR
Table B.1 P.C. Board Status Lights
INCH UP INCH DOWN
SWITCH SWITCH
PRESSED PRESSED
ON
ON
ON
ON
ON ON
ON* ON*
ON
ON ON
ON
ON
ON
Table B.2 P.C. Board Status Light Definitions
FUNCTIONS INDICATED BY PC BOARD LEDS
INCH UP SWITCH PRESSED
LOGIC SIGNAL FOR MOTOR TO RUN
DOWN FIELD VOLTAGE APPLIED
UP FIELD VOLTAGE APPLIED
ARMATURE VOLTAGE APPLIED
START SWITCH PRESSED
STOP SWITCH PRESSED
WELD CURRENT PRESENT
SIGNAL TO APPLY DOWN FIELD VOLTAGE
INCH SPEED CIRCUIT OPERATIVE
SIGNAL TO ENERGIZE TRAVEL CIRCUIT
INCH DOWN SWITCH PRESSED
SIGNAL TO OPERATE POWER SOURCE CONTACTOR
WELD VOLTAGE CONTROL OPERATIVE
GROUND LEAD PROTECTOR "TRIPPED"
ELECTRODE VOLTAGE (OUTPUT FROM VV BOARD)
ELECTRODE VOLTAGE (INPUT TO VV BOARD)
LT-7 TRACTOR
START STOP BURNBACK
SWITCH SWITCH MODE
PRESSED PRESSED
ON
ON
ON ON
ON
ON
ON
ON ON
ON
ON
ON
ON
ON
ON
B-21
GROUND
LEAD
PROTECTOR
TRIPPED
ON ON
ON ON
ON*
ON ON
ON
ON
ON
ON