Despite the blue color, the 120mm cooling fan is a relatively common Yate Loon D12BH-12. This particular model has a ball bearing and a maximum speed of 2300RPM; a notably better and more powerful fan than that of the ST50F-ES.
Although both units share the same output, the ST50F-P is an entirely different design and from a different OEM. Fortron (also known as FSP) is the manufacturer of the ST50F-P. The heatsinks are notably better, as is the quality of the assembly, which is well above average, especially considering the price range of the power supply.
The filtering stage begins at the behind of the A/C receptacle and continues onto the main PCB. We counted four Y capacitors, two X capacitors and three filtering chokes. Unfortunately there is no MOV; Fortron has a habit of not using MOVs as the company claims that their usefulness has been made obsolete by the APFC circuitry.
A CapXon 270uF/420V capacitor and a fairly large coil are the passive components of the APFC stage. The active components, two transistors and a diode, are on the large heatsink, alongside the single AC rectifier. The smaller heatsink next to the primary side of the main transformer holds the primary inversion transistors, which form a half bridge configuration.
The DC generation is again based on a simple topology, making use of diodes and group regulation, yet not as basic as the design of the ST50F-ES, as this time two transistors hold the 12V line, two the 5V line, one the 3.3V line and one the 5VSB line. The secondary side capacitors are supplied by Teapo and CapXon. Unfortunately, the secondary side is badly crowded by the many cables transferring the power onto the vertical PCB, which holds the modular cable connectors.