DIYers IT Zone

Power supply is one of the important component in our PC. But it seldom take into serious by most of the users. We can easily get a cheap 450W power supply with around RM45. But if we really can a good power supply, it cost few hundred ringgit… Some common branded are likes Cooler Master, Acbel, Enlight, Antec and etc. We can easily few the differences between cheap and expensive power supply. The latter always with some weight and more connectors while the cheap PSU is very light and less connectors.

Typical symptoms with power-supply failures:

• No indicator lights are visible, with no disk drive action and no display on the screen. Nothing works, and the system is dead.
• The On/Off indicator lights are visible, but there is no disk drive action and no display on the monitor screen. The system fan might or might not run.
• The system produces a continuous beep tone.

Standard power supplies turn the incoming 110V or 220V AC (Alternating Current) into various DC (Direct Current) voltages suitable for powering the computer’s components.

Power supplies are quoted as having a certain power output specified in Watts, a standard power supply would typically be able to deliver around 350 Watts.

The more components (hard drives, CD/DVD drives, tape drives, ventilation fans, etc) you have in your PC the greater the power required from the power supply.

By using a PSU that delivers more power than required means it won’t be running at full capacity, which can prolong life by reducing heat damage to the PSU’s internal components during long periods of use.

There are 3 types of power supply in common use:

• AT Power Supply - still in use in older PCs.
• ATX Power Supply - commonly in use today.
• ATX-2 Power Supply - recently new standard.

Bundle with power supply, we can see a lot of connectors.

4 Pin Berg Connector
Used to connect the PSU to small form factor devices, such as 3.5″ floppy drives.
available in: AT, ATX & ATX-2

4 Pin Molex Connector
This is used to power various components, including hard drives and optical drives.
available in: AT, ATX & ATX-2

20 Pin Molex ATX Power Connector
This is used to power the motherboard in ATX systems.
available in: ATX( ATX-2 have four extra pins)

4 Pin Molex P4 12V Power Connector
Used specifically for Pentium 4 Processor Motherboards.
available in: ATX (integrated into the power connector in ATX-2)

6 Pin AUX Connector
Provides +5V DC, and two connections of +3.3V.
available in: ATX/ATX-2

Connectors Pins

The PSU, if not connected to motherboard, we cant “on” the PSU even if we apply power to it. ( U will notices that the fan on the PSU not working )To enable PSU individually, under the main power connector, we need to “short” the PS_on and GND pins with some metal such as paper clip. By doing this, we can use the power supply as an 12VDC, 5VDC, 3.3VDC sources.