Chapter 7 Power Supply And Distribution; Introduction; Power Supply Assembly/Control; Figure 7-1. Power Supplya - Compaq Deskpro 4000N Technical Reference Manual

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 4000N and 4000S Personal Computers. All models use a 76-watt power
supply assembly. Power distribution is basically similar in all models. Topics covered in this
chapter include:

Power supply assembly/control (7.2)

Power distribution (7.3)
Signal distribution (7.4)
7.2 POWER SUPPLY ASSEMBLY/CONTROL
This system features a power supply that is controlled through programmable logic (Figure 7-1).
This allows several options for how and when the system can be powered up.
Power
Button
SW1 -6
AC Input
Figure 7–1. Power Supply Assembly, Block Diagram
page 7-1
page 7-4
page 7-6
System Board
Power
PINTA
Control
On Cntrl
Logic
+5 AUX
PS On Fan Off-
+3.5 VDC
Power Supply
Assembly
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
Technical Reference Guide
Power On
NIC
I/O Controller
Fan Pwr
Fan
To
+5 VDC
System
Board &
-5 VDC
Drives
+12 VDC
-12 VDC
7-1