A standard Globe S1202512L 120mm fan is being used for the cooling needs of the ST50F-ES. It is a fairly simple product with a sleeve bearing and a maximum speed of 1800RPM.
The OEM behind the Silverstone ST50F-ES power supply is High Power (also known as Sirtec), a manufacturer known for their expertise on low-cost designs. The design of the ST50F-ES is indeed very basic and the manufacturing quality is mediocre, with numerous soldering joints looking rashly done and a lot of glue in charge of enhancing the mechanical cohesion between components.
The filtering stage is quite strong, beginning at the behind of the A/C receptacle and continues onto the main PCB. We counted four Y capacitors, three X capacitors, two filtering chokes and a MOV; more than enough components for a good filtering stage.
The active components of the APFC stage are attached to the heatsink near the edge of the PCB, alongside the AC bridge rectifier. A medium sized coil and a 400V/220uF capacitor supplied by Su-Scon are the passive components of the APFC stage. Three transistors can be found on the primary stage heatsink of the power supply, two forming a half-bridge inversion circuit and one is responsible for the 5VSB line.
The configuration on the secondary is quite basic as well, with one transistor for each voltage rail, rectification via diodes and simple group regulation. The secondary side capacitors are all coming from Su-Scon as well. Su-Scon surely is not the unknown off-brand which is usually found in $20 products but also is certainly not the manufacturer of choice when it comes to high quality products either.