Lesson 3System Power

Core Hardware Fundamentals

Objectives

Describe the function of a power supply.

Measure power supply voltages and compare the results to expected voltages.

Identify when the use of an Uninterruptible Power Supply (UPS) would be appropriate.

Identify potential high-voltage hazard areas.

Describe methods for reducing the potential risk from electrostatic discharge (ESD).

Objectives

Describe the power on self test (POST) process.

Describe the role of the operating system in system startup.

Power Terms

Electricity

Conductor

Insulator

Resistance

Circuit

Voltage

Current

Power

Ground

Power Supply Function

Measuring AC Voltages

0 VACNeutral (larger) vertical slot and ground

Neutral to Ground

110 – 120 VACHot (smaller) vertical slot and ground

Hot to Ground

110 – 120 VACHot (smaller) vertical slot and neutral (larger) slot

Hot to Neutral

Expected ReadingLead PlacementTest

AT Motherboard Connectors

BlackGroundP8-6

BlackGroundP8-5

Blue-12P8-4

Yellow+12P8-3

Red+5P8-2

Orange+5P8-1

Standard Color

VoltagePin

Red+5P9-6

Red+5P9-5

Red+5P9-4

White-5P9-3

BlackGroundP9-2

BlackGroundP9-1

Standard Color

VoltagePin

ATX Motherboard Connectors

Yellow+ 1210

Purple+ 59

Gray+ 58

BlackGround7

Red+ 56

BlackGround5

Red+ 5 4

BlackGround3

Orange+ 3.32

Orange+ 3.31

Standard ColorVoltagePin

Red+ 520

Red+ 519

White- 518

BlackGround17

BlackGround16

BlackGround15

GreenPS_On14

BlackGround13

Blue- 1212

Orange+ 3.311

Standard ColorVoltagePin

Disk Drive Power Connectors

Pin Voltage Color

1 + 12 Yellow

2 Ground Black

3 Ground Black

4 + 5 Red

Portable Batteries

Nickel Cadmium (Ni-Cad)

Nickel Metal-Hydride (NiMH)

Lithium-Ion (Li-ion)

Power Protection

Surge Suppressor

Line conditioner

Standby power supply (SPS)

Uninterruptible power supply (UPS)

Power Concerns

Electromagnetic interference (EMI)

Electrostatic discharge (ESD)

Shock hazards

Power supply

Display monitor

Laser Hazard

Laser printer

CD-ROM drive

DVD drive