A Look Inside

Before reading this page we strongly suggest to take a look at this article, which will help you understand the internal components of a PSU much better.


As we already stated, the OEM of this unit is Seasonic, one of the best PSU manufacturers with huge experience and long history in this field. On the main PCB we do not find any large heatsinks, since energy dissipation is kept low thanks to the high efficiency and on top of that the case itself plays a crucial role in cooling down the secondary side mosfets. In order to decrease the amount of wires that transfer DC voltages inside the unit, thus minimize energy losses, the DC-DC converters are housed on the modular PCB and the modular sockets that are fed exclusively by +12V are soldered directly on the main PCB. This why the main 24pin ATX connector from the PSU side consists of two smaller connectors.


The AC receptacle incorporates a complete line filter from Yunpen (YO-T1 series) which includes one X and two Y caps and two chokes. On its terminals we also find another X cap. The remaining components of the transient filter, two CM chokes, one X and two caps and an MOV reside on the main PCB. Right next to the MOV there is an NTC thermistor responsible for protection against large inrush currents and an electromagnetic relay which isolates the thermistor from the circuit once the start up phase finishes, increasing efficiency this way.


There are two GBJ 1506 bridge rectifiers, bolted on a dedicated heatsink. These bridges are way two strong for the unit's mere 650W capacity. In front of them an X cap is soldered; its job is to filter the high frequency ripple.


In the APFC three IPP60R190C6 mosfets are used along with a CREE C3D06060 boost diode. The two parallel hold up caps are provided by Nippon Chemi-Con (330µF each or 660µF combined, 420V, 105°C, KMR series). In order to boost efficiency an LLC converter is utilized.
The main choppers are two IPP60R190C6 fets and the resonant controller is a CM6901 IC. The latter is soldered on a vertical, leaned, PCB.


The standby PWM controller is an ICE2QR4765 and is soldered on the component side of the main PCB.


In the secondary side there isn't any heatsink holding the +12V mosfets, just some smaller heatsinks with wide fins and six polymer caps underneath of them. The mosfets, four IPD036N04L, that rectify +12V are located on the solder side of the main PCB and are cooled passively by the case itself and the three afore-mentioned heatsinks on the PCB's components side. All electrolytic caps in the secondary side are provided by Chemi-Con and Rubycon, a killer combination.


The VRMs responsible for the minor rails' generation are located on the modular PCB. There we find an APW7159 PWM controller and in total eight IPD060N03L mosfets. On the front of the modular PCB we find two small chokes and several polymer caps.


The protections IC is housed on a vertical daughter-board and is a PS223 IC. This IC supports the rare Over Temperature Protection and provides OCP for up to two +12V rails.


Soldering quality on the main PCB is typical Seasonic, very good with nice and clean solder jobs everywhere.


The cooling fan is provided by Sanyo Denki and its model number is 9S1212F404. It uses ball bearings for increased life span and at full speed it makes its present felt. Thankfully in this unit the fan profile is rather peaceful and on top of that at low loads/ambient the unit operates in fanless mode.