The +5VSB Power Supply
The +5VSB (a.k.a. standby) power supply is independent of the main power supply, since it is on continuously.
The +5VSB power supply uses an integrated circuit that incorporates the PWM controller and the switching transistor into a single chip. However, the manufacturer scratched off the marking on the chip, so we can’t say which model it is.
The rectification of the +5VSB output is performed by an S10C40C Schottky rectifier. This component supports up to 10 A (5 A per internal diode at 125° C, 0.55 V maximum voltage drop).