A Look Inside & Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the internal components of a PSU much better. Our main tool for the disassembly of the PSU is a Thermaltronics TMT-9000S soldering and rework station. It is of extreme quality and is equipped with a matching de-soldering gun. With such equipment in hand, breaking apart every PSU is like a walk in the park!


This PSU is by Seasonic, one of the best OEMs with a ton of experience, since they've been around since 1976. Based on the same platform as Seasonic's budget-oriented G units, the design is current because it utilizes an LLC converter in the primary side to minimize switching losses. The secondary side uses a semi-synchronous rectification scheme and DC-DC converters for the generation of the minor rails. All electrolytic caps are also Japanese, which shows that no compromises in build quality were made.


The first part of the EMI filter is installed on a small PCB right behind the AC receptacle and includes four Y caps, a single X cap, and a CM choke. There are two CM chokes, a single X cap, a pair of Y caps, and an MOV on the main PCB.


The single bridge rectifier is a GBU1506. It has been installed to a dedicated heatsink.


In the APFC converter, two SPP20N60C3 Infineon mosfets and a single STTH8S06D boost diode shape the current sinusoidal to make it match the voltage sinusoidal. The bulk cap is provided by Nippon Chemi-Con (420 V, 470 µF, 105C, KMQ series).


A pair of Infineon IPP50R250CP fets act as main switchers. An LLC resonant converter is used to boost efficiency, and its inductive and capacitive parts are shown in the last two photos above.


The vertical daughter-board shown in the last of the photos above houses an ICE2HS01G resonant controller (large IC on the left) and an ICE3PCS01 PFC controller (small IC on the right).


The secondary side utilizes a semi-synchronous rectification scheme with two NXP PSMN2R6 (2R640 PBm 1317D1 markings) fets and two SBR10U45 Schottky diodes that rectify the +12V rails installed on the solder side of the main PCB. A heatsink on the component side regulates their operational temperatures. The minor rails are generated by two DC-DC converters.


Several Enesol polymer caps in the secondary side and a bunch of electrolytic Chemi-Cons (105°C, KZH series) and Rubycons, a dream-team of electrolytic caps, filter the rails.


An Infineon ICE2QR4765 IC acts as the standby PWM controller. The Schottky diode responsible for the rectification of the 5VSB rail is an SBR10U45, and it is located on the solder side of the main PCB.


The supervisor IC is a SITI PS223, one of the very few monitoring ICs that support OTP (Over Temperature Protection) out of the box. The same IC also supports OCP for up to two +12V rails, which matches the specifications of this PSU.


Soldering quality on the main PCB definitely isn't the best we have ever seen from Seasonic, but it is still quite good. However, we would like some component leads to be shorter.


The cooling fan is provided by ADDA, and its model number is AD1212HB-A70GL (120 mm, 12 V, 0.37 A, 2200 RPM max, 85.2 CFM, 39.1 dBA). It uses ball bearings, which will have it last longer than a sleeve-bearing fan.