Dear forum members, Sir, Iam having Lenovo PC, It is useing 180W SMPS, it is built useing two 470 micro farad,400 V capacitors in rectifier circuit,.Each capacitor has single pf capacitor in parallel. as shown in fig. Both pf capacitor has burnt and unable to find it`s value. Please any one can tell how much the value must be..
All i can think of is having a specifically winded transformer that has two secondary coils that gives 130 volts AC each. Or a center tap transformer that takes 220V for the primary and a 130-0-130V as secondary. Then rectify the output and have a regulator to convert it to DC. For the amperage that’s a pretty high rating, you will need a large gauged wire for this project.
You can use 0.1 mfd ceramic 400v or 600v cap in this place. But before replacing capacitors make sure the main switching transistor,zener diode is short or any other component is open or gone high value (resistors) carry out a cold check of the components ie (mains power disconnected condition ) after replacing the faulty components switch on the power supply with out connecting both the 470 mfd and 0.1 cap if the power supply voltage is as per your requirement and below the voltage rating of the capacitors then you can safely connect the caps after disconnecting the mains power. pl review my rating.
