Xerox PHASER 8500 Service Manual page 53

Phaser 8400/8500/8550/8560 Color Printer Service Manual
The DC power supply generates + 3.3 V, +/- 15 V, and +/- 50 V. These
voltages provide direct or regulated voltage values to various circuits in the
printer. The power control board regulates +/- 15 V to +/- 12 and other
voltages. The main board also has regulators providing + 5 V, + 2.5 V, and +
1.8 V. The power supply outputs + 3.3 V in ENERGY STAR mode. Fuse F1
provides protection for the switching power supply in the DC section.
Warning
Do not touch the power supply; AC line voltages are present. The power
switch does not disconnect power from the printer. The power switch
signals the supply and the printer logic to begin a shutdown sequence.
F3
F2
P
D
r
r
e
u
h
m
t
H
8
H
9
AC Line AC Neutral
Low
Switcher
+3.3 V
H13
H12
H11
H10
H9
H8
+15 V
H4
-15 V
H3
+50 V H2
-50 V
H1
AC Line
S1
AC Neutral
r
I I I I
e
n n n n
s
k k k k
2
4 3 2 1
H
1
3
H
1
2
H
1
1
H
1
0
Serial
Control
Interface
Vcc
REG
uProcessor
Vss
Theory of Operation
Line
Gnd Ref
Neutral
r
e
js js
s
r I
1
H
4
H
3
H
2
H
1
s8500-022
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