Brother GTX-4 Service Manual page 330

Power circuit board (SB4721)
F8,F9
PRIMARY FUSE
HARNESS
NOISE FILTER
HARNESS
FILTER GND WIRE
CN15
COIL_IN
CN18
COVER_SW
CN17
COIL_OUT
HARNESS
AC_POWER
Power indicator lamp (constantly ON)
* LD4 and LD5 signifies condition of standby power source, and remains on when main power is switched off with the
power switch and when power is cut by opening front cover.
Disassembly / Replacement / Adjustment
LD1 LD2
ADD5V +31.5V
6-139
CN6
POWER3
CN5
POWER2
CN1
POWER1
CN2
MNT
CN3
MAIN_UART
CN4
DC_IN
CN13
PW_SW
CN14
SW_CTL
LD3
+5V
LD6
+24V
LD7
+36V
LD8
POWER ON
LD4
+5V_SW
LD5
+6.5V-23V