Troubleshooting A Dead Powersupply of any Equipment

In troubleshooting a dead powersupply first step is to look for any visible signed like:

 1. burnt fuse

 2.  burnt components like ic, resistor, diode, etc.

note: look for the culprit why these said components burnt. dont just replaced them

 3.  bulged capacitors

 4. dark spot or burnt

on the board it can be a clue if you cannot find the culprit the near components their might be a            suspect.




5. If you cannot find  the above clue. It's time to to used to digital multimeter, capacitor tester, esr meter, ringer.

Work your way in to out. Start on the plug. Check for continuity, it should be 0000 reading in your meter  both line not 100  to be sure ac plug have good continuity or else you will missed the culprit that's why there is no 220 volts ac coming to your plug. Note: for checking continuity and each components for resistance  the plug of equipment should be unplug. After checking for plug follow th fuse for continuity for open and diode for short or leakage , etc. You can used also  ringer to test for the primary winding of switch mode transformer. You can trace the primary by following the positive side main filter of electrolytic caps usually with 200 or 400 volts going to the pin of transformer. on the otherside the drain pin of fet or power ic going to pin of the transformer that' the primary side. if you ring it, it should have 7 or 8 led lits that is the sign the winding is good and the fet is good also but not most on power ic. if you are not good on testing electronic components click on the book above on the right side.

Check for 300 volts something to your main filter capacitor. It should have if your primary side of power supply is working.

 and also check if voltage also is present in drain pin of fet or power ic. if you dont look for the datasheet in the internet type its part number. I f the voltage is present chance are your primary side of smps is good.

Move your focus on the secondary side if there is output coming out of filter capacitor, like 5 volts, 12 volts, 3.3 volts etc. look on the board. if you did not get check for the esr of electrolytic capacitors if it high esr or there is components on the secondary side that is bringing down the voltage of one the said line.

note: if the capacitor is good in secondary side and still you cannot get one or two of the ouput voltage try unplug the socket that is connected to mainboard may be there is problem their. like shorted microcontroller unit ic or other components. if the voltage came back after you unplug the socket the problem is in the mainboard.