Generic Repair And Test Procedure For Smps.docx

Generic Repair and Test procedure for Rectifier Units of different models 1. Test Setup Required Quantity 1 1 1 1

Description AC 230V Supply Multi meter Oscilloscope Power Supply Unit(UUT) 2.

Troubleshooting and testing process

a. Visual inspection has to be carried out for physical and electrical damages. b. If the unit is found to be damaged due to water logging, burning or any other way that cannot be recovered, then it is declared as BER. c. After visual inspection and before switching on the Power Supply unit, Check Fuses and it is mandatory to confirm with Multi meter that there is no electrical short presents between input and output supply pins, d. Check whether there is any electrical short present in Power factor and Switching MOSFETs in the rectifier. e. If there is any short presents remove and change with the new components. f. It is also mandatory to confirm that there is no short or open in the MOSFET driver section. g. Also check the short between VCC and GND pin of the ICs in the Power factor, Switching and Feedback sections. h. Change the faulty ICs if there are any short presents. i. If these check points are ok then this Board is Ok. j. Assemble the Boards and now the input supply can be given to the unit. k. Power on the board and Monitor the LED Status. There should not be any Major Alarm indication (like Rectifier Fault, Fan Fault, Over Current, etc.). l. After that check the rectifier DC output voltage, if the voltage presents check the secondary voltages are generated. m. If there is no output check the AC input to the rectifier. n. If secondary voltages (12V, -12V and 5V) not generated. Check the secondary voltages section. o. If any alarm presents after unit powered on and there is no output. Check the section according to alarm description. These alarms can be varied according to different models.

WI- 280219_6

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