Hi, I'm hoping someone can recognise this diode. I have two that need replacing in the oscillator circuit of a large switch mode power supply and would rather not guess. Searches have got me no where. See attached images. Thanks for any help.
SMD marking code AB, W43 is china
BAS16SL (SOD-923F On-semi/Fairchild)
MAZU200-H 200V zener diode (SOD-323FP) -seems a bit HV for that IC.
PESD3V3L1BA ESD protection diode (SOD323) -not likely as back to back.