Download Power Supplies

By Jono, Phil, Dan, Gareth
What are Power Supplies
 A power supply converts AC current from the wall socket to
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DC current to run the computer.
AC current stands for Alternating current which comes
through the wall sockets. Good for high current appliances.
DC current stands for Direct current as the current coming
in does not change because of positive charge pulling the
negative charge towards it in a direct flow.
Power supplies Generally come with a switch to change it
from running from 110v(united states) to 240v (UK voltage.)
Power supplies are rated in Watts, the more higher current
devices you run the higher the watts need to be.
Form Factor of Power Supplies
 Power supplies are attached to the motherboard by
connectors i.e. Molex connectors so therefore the
power supply must match that of the motherboard
specs.
 So If you have a ATX motherboard then you need an
ATX power supply.
 Also if you have high end gaming components like an
8800 Ultra graphics card then you would need a high
wattage power supply.
Symptoms of Bad Power Supplies
 The power supply does not start, this could be due to
faulty wires or not turned on at the socket.
 The system Shuts off, this might be due to a sudden
loss of power by a brownout or a blackout.
 The Fan on the power supply is noisy, this might be
due to dust accumulated on the fan and has to work
harder to get the required cooling within the power
supply.
Testing Power Supplies
You can test a power
supply by using a
specially designed tester
like the one in the video
where you plug the
connectors into it and
lights will show if its
working or not.
Removing the Power supply and
Connections
The first video is the removing of the connections to the
motherboard and other devices like CD drive.
The second video is removing the power supply its self , it
is normally held in by 4 screws.
Installing and Reconnecting New
Power Supplies
The first video is the power supply being inserted back into the case and
screwed back in.
The second video is reconnecting the connectors like the ATX and the
Molex's back to their respective devices.
A Working Power Supply
This is when the new power supply has been connected
successfully as the fan starts operating.
Thank You for Watching
our Presentation