Now connect the negative output and the alligator clip to the positive output supply on the 5 volt VCC pin on the main board as shown in the picture. Once everything is done, it’s time to turn on the DC regulated power supply. Gradually detach the knee clockwise and observe the voltage increase. At the same time the current draw can be viewed from the current digital meter readout with fcw dc adaptor price. Empirically, if the main board has a short circuit, whenever the voltage increases, the flow will increase dramatically and if there is no short circuit there will be less current draw.
Well, for this problem, if you notice that the current (also) voltage setting is increased proportionately, you are now making sure that the component on the main board is small. What does this mean? This is good news for us, because if the current draws too much, we can know the culprit by touching the hottest elements in the main board. Using your finger you can touch any ingredient that is too hot. Touch on IC, diode, transistor, and capacitor and so on. Once you’ve located the only ingredient that’s too hot to touch it was the culprit! This is the real reason you are trying to find out! I have used this method to solve many of the main board problems and the culprit can usually be a faulty gate array and RAM IC.
I do not immediately turn the output voltage up to 5 volts from the DC voltage controlled power supply because even the faulty main board uses 5 volts to operate? If I do this and if the defective components get heated up too fast, I’m afraid it will take the defective component to the open circuit. If the faulty component is an open circuit, the current draw will drop and you should show the only key that the culprit is destroyed! If this happens, you won’t have a rate for board repair. Of course you can change the SMD Spider IC one by one, but it will definitely use up your repair time.
The above method I just mentioned is not limited to the printer main board at the affordable fcw adapter price; This can be applied to other types of boards as well as computer motherboards, hard disks, DVDs, VCDs, industrial experimental boards, etc. Get the DC regulated power supply and I am sure you will be able to find the main components across the board in as little time as possible. By the way the DC specification controls the power supply I’m using 5A 30 volts (variable type).
Troubleshooting linear power supply was significantly easier than module power supply (SMPS). The AC voltage enters the primary side of the linear transformer and then converts the AC to a lower or higher AC voltage depending on the secondary winding. The output AC voltage is then purified and filtered by the diodes and capacitors to produce a clean DC voltage. If there is a problem with the linear transformer circuit, I can say that the fault is very easy to detect. This is somewhat different in the case of switch mode power supply. The design was complex and it was difficult for some technicians to understand how the switch mode power supply works.
Switch mode the working principle of the power supply is different from the linear type. The first AC voltage will flow into the full wave rectifier (the bridge rectifier) which produces uneven DC output and is then filtered through a large capacitor (usually up to 220 micro fades and 450 volts). The clean DC voltage will then flow to the input of the starting resistors and the switch mode power transformer. Once the voltage is passed through the five ohm resistor (start resistors), the voltage goes to a value from which it flows into the VCC supply pin of the pulse width modulation IC.
Once the PWM receives the IC voltage it will generate a signal to operate the transistor (or FET) and the magnetic field changes in the transformer primary winding. The changing magnetic field induces voltage in the secondary windings. Each of these AC voltages produced by the secondary winding is then fixed, filtered, and regulated to produce a clean DC voltage. One of the main DC output voltages is B + which supplies the flyback transformer (for TV and monitor circuits).Output from the B + voltage supply is connected back to the PWM IC via a “Feedback” loop (which includes the To Psoisolator IC and Error Amplifier TL431 IC). When the voltage from the B + supply increases or decreases slightly, the PWM will work to improve the IC output.
