Compaq Deskpro 4000 - Chapter 7 POWER SUPPLY AND DISTRIBUTION; 7.2 POWER SUPPLY ASSEMBLY;CONTROL

Technical Reference Guide
Compaq Deskpro 4000 and 6000 Personal Computers
featuring the Pentium II Processor
First Edition - October 1997
7-1
AC Input
To
System
Board &
Drives
Chapter 7
POWER and SIGNAL
DISTRIBUTION
7. Chapter 7 POWER SUPPLY AND DISTRIBUTION
7.1 INTRODUCTION
This chapter describes the power supply and method of general power and signal distribution in
the Compaq Deskpro 4000 and 6000 Personal Computers featuring the Pentium II processor. All
models use a similar switching-type power supply. The desktop unit employs a 200-watt supply
while the minitower unit features 280-watt supply. Power distribution is basically similar in all
models. Topics covered in this chapter include:
♦ Power supply assembly/control (7.2) page 7-1
♦ Power distribution (7.3) page 7-4
♦ Signal distribution (7.4) page 7-6
7.2 POWER SUPPLY ASSEMBLY/CONTROL
This system features a power supply assembly that is controlled through programmable logic
(Figure 7-1).
Figure 7–1.
Power Distribution and Control, Block Diagram
Power Supply
Assembly
Power
Control
Logic
+5 VDC
-5 VDC
+12 VDC
-12 VDC
+3.5 VDC
Power On
Power
Button
S
y
stem Board
PS On
Fan Off-
+5 AUX
NIC
I/O Controller
PINTA
On Cntrl
Fan
Fan Pwr
SW1 -6