Computer Power Supply is the main power source that provides voltage + 12V,-12V, + 5V,-5V, and the signal POR (Power On Reset) to activate the motherboard. Maximum power that can be consumed by the power supply is about 200 watts with input voltage of 220 V AC from PLN. With a very high efficiency power supply is about 200 watts to provide a voltage of + 5V with a current of about 15-20 A for the purposes of digital equipment motherboards, disk drives, hard disk, processor fan, CD-Rom Drive and what cards are aimed at motherboard slots.
When the load power supply is excessive, then the computer will not walk or can walk but not normal especially when electricity is needed to increase up to the limit. The damage that often occurs is due to overload, unstable voltage, which is not good ground system, and other causes. The most fatal disorders for for power supply voltage is when no issue at all, despite being given a voltage in accordance with needs. Practical ways to improve the computer's power supply could be made as follows:
[1]. Disconnect the power supply box for easier checking of Cassing electronic circuits and disconnect all cables from other tools. Open the power supply box, checking physical electronic components, perhaps there is a fire can be known.
[2]. Check the insert FUSE 220V AC external power source, disconnect it from the socket FUSE and measure the safety wire ties with ohm-meter at the position X1. Ohm-meter needle should indicate a value of about 0 ohms, which means that FUSE is still good. If the ohm-meter shows the number of infinite, then FUSE has been broken, should be replaced new. Do not make the connection wire on FUSE that had broken, because the melting current limit will probably be larger and will cause damage to other parts.
[3]. If FUSE either new or have been replaced but still can not exclude the DC voltage, then proceed to examine the switching power transistor 2SC3039 (two pieces), which served as the control of a PWM power supply. Remove the two 2SC3039 transistor from the PCB and do check the condition of each one with a multimeter. If one transistor is damaged to replace them should they be replaced with a new transistor, for secure and symmetrical characteristics, the imbalance is characteristic of the two transistors causing a disturbance voltage stability issued DC power supply.
[4]. Remove the diode brigde or four pieces of direct diode rectifiers AC power leveling on the insert, check the condition of this diode with a multimeter. Sometimes this was one of the diode leakage or short-circuit, so that the AC power coming in to the circuit switching and disabling the power supply as a whole will follow the power transistor is damaged, fire. Even if this diode leakage rate is very large, it will melt the switching transformer, wire peeled off, and connect short, this is the most fatal damage.
[5]. Also check transistor pulse generator "power on reset", also contained kapasisitor and resistors in the circuit of the transistor base. If the transistor circuit is working properly, then the entire DC voltage regulation will result in reset by the PWM generator and consequently does not issue a DC power supply at all. Replace the new transistor if the transistor POR testing proved defective. So, when the capacitor in the test will be dry, its value changes, the new must be replaced with the exact same value as before.
[6]. Because the computer power supply generally work with higher temperature than room temperature, then there is a possibility because of excessive heat caused solderan legs or component cables there is an independent. Check all solderan on PCB Power Supply, better still make sure to do the repair with the way in re-tin solder is softer (thinner, fluxes 60/40). So the cable connection or foot components that may be loosely knit can be guaranteed and generally power supply will be able to work normally again.
[7]. Pengetesannya active component can not be done with a multimeter is ICTL494 who served as a PWM generator to control power transistor switching work. IC is only in the test by comparing to the IC mode at a power supply of other kinds. Use IC sockets suspected broken with comparator IC is still good.
[8]. When the process of inspection and replacement of damaged components have been done as a whole, then try the power supply is turned on by placing the burden of disk drine only. Check if the fan rotates, measuring stress the yellow wire (+12), red (+5), blue (-5), blue (-12), orange (POR) on the black wire (ground). When the parameters of voltage on the cables are correct, turn off the power supply and replace the load with the motherboard or a full load as before, try again.