Ch5 Power Flashcards
What is the measurement of potential energy?
voltage
sag
Unexpected decrease in the amount of voltage provided.
You just upgraded a motherboard in a computer, and put the system back together. It boots , but the power LED on the front of the computer case doesn’t light when the system is on. The rest of the computer seems to work fine.
What should you do first?
Check the power LED pinout.
You are troubleshooting a computer that won’t power on. You have already checked the AC outlet and the power cord, which appear to be functioning properly.
What should you do next?
Test the computer with a PSU tester.
What voltage reading should a hot / ground measurement be?
115 -120 V
What is an unexpected increase in voltage?
spike or surge
Name the Connector

Mini (Berg) Power Connector
What tool would you use to test the amount of voltage that come from an AC outlet?
multimeter
Number of joules recommended in surge protector?
1000 or greater joules.
Steps of A+ Method for Testing Wall Socket with Multimeter
- Place multimeter’s black lead in outlet’s ground.
- Place red lead in hot opening.
- Turn on multimeter to measure for AC (VAC)
- Turn off multimeter
- Remove the red lead.
- Remove black lead.
What power connector would be used to power an IDE Hard Drive?
Molex
Name the Connector

Molex Power Connector
Four Types of Common Power Connectors on Power Supplies
- Molex
- Mini (Berg)
- SATA
- PCIe
Type B Wall Power Socket Layout
- Left Side (Large Slot) = Neutral
- Right Side (Small Slot) = Hot
- Bottom (Semi-Round Slot) = Ground
A company salesperson just returned to the US after 3 months in Europe. Now the salesperson tells you that the PC, which worked fine in Europe, won’t turn on.
What is the best solution?
Change the voltage setting from 230V to 115V
It is recommended for a laser printer to be plugged into a UPS (T/ F)
False; due to the high current draw a laser printer should not be plugged into a UPS.
Which device should you use to protect against power outages?
UPS
A computer you are troubleshooting shuts down without warning. After a few minutes it boots back up fine, but after running for a short time, it shuts down again.
What two components could be the cause?
- Power Supply
- CPU Fan
Molex Power Connector Usage w/ Pins and Voltages
Case fans, IDE hard drives, and optical drives.
4 Pins
Red (5V), Black (Ground), Black (Ground), Yellow (12V)
Number of pins in ATX 12V 1.0 - 1.3 Power Supplies
20 Pin Connector & 4 Pin 12V Connector.
SATA Power Connector Usage w / Pins and Voltages
Serial ATA Hard Drives and optical drives.
15 pins.
3.3V, 5V, and 12V
What device tests multiple wires of a power supply at the same time?
Power Supply Tester
Number of pins in original ATX power supplies.
20-pin connector
Name the Connector

SATA 15 Pin Power Connector
brownout
Voltage drop that results in light dimming and computers / electronics to shut off momentarily.
Name the Connector

PCIe 6-pin Power Connector
Mini(Berg) Power Connector Usage w / Pins and Voltages
Floppy Drives
4 Pins
Red (5V), Black (Ground), Black (Ground), Yellow (12V)
PCIe Power Connector Usage w / Pins and Voltages
PCI Express Video Cards
6 Pin (ATX v2.1) 12V
8 Pin (ATX v2.2 and higher) 12 V
You suspect that incorrect voltage is provided to a power supply.
What tool should you use to test this?
Multimeter
Red and Black Lead Polarities in Multimeter
- Red = Positive (hot)
- Black = Negative (ground)
What voltages are supplied by a molex power connector?
12 V and 5 V
What voltage reading should a neutral / ground measurement be?
0 V ; Any other measurement indicates improper grounded outlet.
Number of pins in newer ATX 12V 2.x Power Supplies
24-pin connectors.
You want a cost-effective solution to the common surges that can affect your computer.
Which device would be the best solution?
Surge Protector.
You are fixing a computer for a customer when you notice a few of the fluorescent lights flickering every now and then.
What should you recommend to the customer to protect their equipment?
Install a UPS
spike
Short transient in voltage that can be due to short circuit, tripped circuit breaker,power outage, or lighning strike which is more powerful than a surge.
Which wire when tested should display zero volts on a multimeter?
Ground
surge
Unexpected increase in the amount of voltage provided.
What form factor uses a 24-pin main motherboard connector?
ATX 12V 2.0