Lincoln Electric PRO-CUT 55 Service Manual page 77

F-39
CONTROL BOARD LED DEFINITIONS
LED1: (Red) This light indicates that 18 VAC is
being supplied to the control board from the
auxiliary transformer. It also shows that the 18
VAC is being rectified and should be regulated to
+15 VDC. This +15 VDC supply is used to power
the circuitry on the control board.
#216
TROUBLESHOOTING & REPAIR
LOW VOLTAGE CIRCUIT TEST (continued)
FIGURE F.14 – CONTROL BOARD LEDs
PRO-CUT 55 CONTROL G3328
LED2
LED1
LED3
FIGURE F.15 – DISPLAY BOARD TEST POINTS
L10721 DISPLAY BOARD
J 40
15
#219
PRO-CUT 55
LED2: (Red) This light indicates that the +5.5
VDC is present. This voltage is derived from the
+15 VDC supply. The +5.5 VDC supply is used
to power the circuitry on the control board.
LED3: (Red) This light indicates that 18 VAC is
being supplied to the control board from the
auxiliary transformer. It also shows that the 18
VAC is being rectified and should be regulated to
-15 VDC. This 15 VDC supply is used to power
the circuitry on the control board.
(REAR VIEW)
1
F-39