Many of the components are marked "NC" and they are placed where alternative components can be fitted, for example synchronous rectifiers or simple diodes. It would help to know which are fitted in the model causing your problem.
Brian.
Thanks your comment, since I want to step by step to develop the smps, so I based on the evaluation board to start develop, In the beginning, you are correct, to observe much clear, I modify the schematic and delete those NC component.
My hunch is that it's something with the synchronous rectifiers. The NCP4304 is specced to work with a QR flyback, but the way you're using it is very different from the datasheet. I really hope that the arrangement of F4, D8, and D22 is a typo, otherwise that's guaranteed to blow. If you remove F4 entirely, does it still work?
Also 1N4148 is a poor choice for high peak currents in gate drivers.
Yes, the NC marked are no component at there, since I am the newbie for SMPS, to avoid too complicated circuit, I just seperate 3 section to construct the SMPS, 1: flyback, 2: PFC, 3: synchronous rectifiers, at the first try, the flyback is ok, can regulate to my desired voltage and functional by e-load, next step I add the PFC MOSFET and transformer to form PFC, when first and second try, it also ok both voltage range and current consumption. However, I just on and off the e-load two or three times, the current sense is blowed.
I will add back the synchronous rectifier if it is must.
For the diode, did you mean D3 and D18? any suggestion to change? or use 1N4004 instead? thank you!