A+ 1001: Power Supply Flashcards
Auto-sensing power supply
Senses power input and auto adjusts
Step Down Transformers
PSU are step down transformers that converts AC to DC
ATX Power connector
20 to 24 pin connector
Yellow: 12volt:
Red: 5 volts
Orange 3.3 volts
ATX12v
Extension Power connectors that provide extra power to mother board
Molex
Mini connector
Connectors coming from the power supply
- ATX
- ATX12V
- Molex (peripherals)
- Mini connectors (peripherals)
- SATA power connection (drives)
- PCI-E connector (video cards)
What makes modular connectors different
The cables are not soldered to them, which means you only have to attach the cables that are needed, it makes cable management easier.
The trade off is that the modular connections loses a bit of efficiency
How calculate the required wattage of power supply
multiply the total amps of all components by the total volts of all components
Many modern gaming systems with a 6 or 8-core CPU and a midrange to high-end graphics card should get by with a 650W to 850W power supply, with 750W being a long-time sweet spot for gamers. More powerful hardware requires higher wattages, especially if you plan on overclocking
What factors to consider when choosing a PSU
- Required Wattage
- Room Temperature
Building to about 50 to 60 percent of a PSU’s capacity is advisable to achieve maximum efficiency and yet leave room for future expansion.
80 plus rating system
A standard that guarantees PSU efficiency at 80%
What happens when a system overheats?
Reboots
How to reduce fan noise?
use bigger fans that turn slower but move the same amount of air
PWM connectors
4 pin connectors that are used by the CPU to modulate fan speed directly
How to regulate temp of system?
set temperature warnings in the BIOS
Set temperature a little lower than the cpu max
How to regulate temp of system?
set temperature warnings in the BIOS
Set temperature a little lower than the cpu max
Which component within a computer is the most likely to die?
Power supply
Slow death of PSU.
The primary capacitors that act as surge surpressors start to break down, which results in a slow death.
Symptoms:
- Unexpected shutdowns
- unplug it and replug it then it works for a while
Testing PSU
voltage tester
- look for voltage drops
Fan Spin Test
- connect PGW (green wire), with any ground wire (Black wire) using a paperclip, and see if the fan spins
Motherboard Test
- plug into old motherboard
- Set Voltmeter to 20V DC
- Red Pin to yellow wire(12V)
- Black pin to black wire (ground)
- connect pins that attaches to on button, using a hairclip or jumper
- Read Voltage
If voltage drops to 11.5 then get a new power supply.
Test core components before mounting to case
Startup computer to bios screen
- Check that fans are spinning
- Check for POST error codes
- Check for onboard LEDs
- Check BIOS to see if hardware is connected
- Boot to windows from thumbdrive and perform a memory diagnostic
if the computer is dead then start over and reassemble the build.
if you get system lockup, clear the CMOS jumper
Cause of dead PC
Incorrectly installed CPU’s or RAM (Reinstall)
Error is system setup (Clear CMOS jumper)
Power supply not connected (check connections)
A power supply with optional cable plug-ins is known as a what?
A modular power supply simplifies cable management by enabling you to add and remove optional plug-in cables as needed to power components.
What does the on/off switch on a power supply do?
It allows power to flow from the plug into the power supply.
The four/six/eight pin connector (known as the P4 connector) on the ATX 12V power supply provides power to which computer component(s)?
The ATX 12V power connectors send power to the CPU
Which is a primary characteristic to be considered when choosing a power supply?
Efficiency is a major consideration.
Which is the quietest cooling solution
Liquid cooling is the quietest solution. Fan noise varies depending on size and speed, but small fans (which have to spin faster to move the same amount of air) tend to be louder than large ones. SpeedFan is a fan controller program, not a cooling solution.
What is the primary result of overheating the CPU?
CPU overheating causes shutdowns and reboots.
Overheating does not increase or decrease performance.
Overheating does not cause fans to spin faster.
The voltages output by a PSU can be checked with which tool?
Power supply test tool can test the voltages
Catastrophic (fast) power failures typically include which symptom?
Catastrophic power supply failure may be accompanied by a burning odor. A catastrophically-failed power supply is dead; it cannot provide enough power for slow performance or rebooting. Power supply voltage decay over time is a symptom of a slowly failing power supply.
Unexpected noise coming from inside a running computer likely comes from what?
Cables or loose items in a case that contact spinning fan blades causes unpleasant and unexpected noise. Failing RAM only generates beep codes during the POST process at boot up. Failing speakers and overheated CPUs don’t usually make noise
If installed RAM does not show up in the CMOS setup program, what is the best course of action?
Reseat the Ram modules
