SMPS out put flickering

[ismailpp2008]

in my Tecktronics TDS100c model internal SMPS is from Emerson , it has been damaged , its TOP244yn IC is gone bad[smoke is there near] , so i replaced with new one , after that out put is coming 3.3v but it will on at 2sec and off at 2sec and repeating , what should i change .see the attached smps photo

 

[alec_t]

The usual recommendation is to replace any electrolytic capacitor which shows signs of bulging or leaking. In addition, about half-way up the left side of your pic (just above the big 450V cap), the solder joints of the legs of the component clamped to the heatsink look dodgy.

 

[2PAC Mafia]

You should check the Mosfet which is in serial to the transformator. Also check the values of coils at transformator if you have LCR meter looking for a short circuit between coils or bad Q value. You also must check the secondary diodes and power supply for PWM IC, sometimes it takes power from rectified voltage auxiliar coil at transformator.