By Jono, Phil, Dan, Gareth

What are Power Supplies A power supply converts AC current from the wall socket to 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.

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