A Look InsideBefore reading this page we strongly suggest to take a look at this article, which will help you understand the internals parts of a PSU much better.
The OEM is Seasonic and to be more precise the HCG-620 is a rebadged SeaSonic S12II 620. It seems that lately we've seen a lot of the S12II series, since the two previous PSUs we reviewed were based on S12II 520 and S12II 430 platforms respectively.
The first part of the EMI/transient filter is located on a small PCB right behind the AC receptacle and consists of one X, four Y capacitors and one coil. The second part is on the main PCB and has two coils, one X and two Y capacitors and an MOV.
The bridge rectifier is a GBU1006 which is cooled passively by a heatsink. In the APFC we find two mosfets (SPP20N60C3) and the boost diode. The smoothing capacitor is provided by Nippon Chemi-Con (85°C, 560 μF, 400 V). As main switches we find two SPP20N60C3. Also in a vertical daughter-board right behind the main capacitor resides the combo PFC/PWM controller, an Infineon ICE1CS02.
In the secondary side we immediately noticed the two, only, toroidal coils in the filtering/rectification section of the DC outputs. This means that the PSU uses an outdated group regulated design, so don't expect top performance at crossload tests. For generation of the DC output voltages a passive design is used and there are three 30A50CT SBRs (Schottky Barrier Rectifiers) for +12V, one 40U45CT for 5V and one STPS30L30CT for 3.3V. In the solder side of the main PCB there is an SBR10U45 that rectifies the 5VSB rail. All filtering capacitors in the secondary side are provided by Nippon Chemi-Con and are rated at 105°C. We also found a lonely Rubycon (105°C). Finally, the protections integrated circuit is a PS223 and is housed on a daughter-board in the secondary side. It supports all the protections that the manufacturer claims (OCP, OVP, UVP, SCP).
The soldering quality of the main PCB, for sure, is not among the best we have seen from Seasonic, however is above average.
The cooling fan is provided by ADDA (ADN512MB-A90) and according to Antec at full load the fan works at 1700 RPM and generates 30 dBA noise.