SMPS

SMPS stands for Switch Mode Power Supply.It is the main Power Supply Unit used  to convert the alternating current (AC) power available in homes into direct current (DC) required for a computer system.

TYPES OF SMPS

There are two types of SMPS:-

1-AT SMPS(Advance Technology)

2-ATX SMPS (Advance Technology Extended)

 In AT SMPS system we have to manually Shutdown the computer. After giving Shutdown command

 “It is now safe to turn off your system” message appears then press the power button to shut down.

 In ATX SMPS shutdown is automatic, that is just give the Shutdown command.



 TO CHECK WETHER SMPS IS WORKING OR NOT

Take a small piece of wire and connect one end in GREEN wire port and other in the BLACK. Switch ON the supply if the fan in the smps is working the smps is good. If not open the cover and check whether the Capacitors inside the Smps is bulged on the top. If bulged replace the capacitor with the same value of the earlier.Check the voltages with a multimeter.

Main Power Connector of Motherboard

 A Good ATX SMPS wires gives the following voltage as the output. And work for different purpose

WIRE         VOLTAGE      FUNCTION
      
Black                 0                  Ground
Blue                 -12                 Serial Data
Brown/Violet    +3.3               Sensor
Gray                  +5                  Power good supply
Green                +5                  Power supply on/off
Orange              +3.3               D Ram Refreshing
Purple               +5                  Stored by voltage
White                -5                   Refreshing Ram
Yellow              +12                Motor Rotation
Red                  +5                   Logic circuit

In case of a defect or problem with power supply, it is not recommended that an inexperienced user open a power supply for repairing. The power supply has dangerously high voltage.

CONNECTORS FOR POWER SUPPLY
 

ATX POWER CONNECTOR

SATA DRIVE POWER CONNECTOR