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 noted Coolermaster dropped Seventeam and uses a different OEM for the refreshed GX series. Identifying the OEM Enhance is easy because of the large heatsinks and their design, also the black&white colored wires that transfer power from the AC receptacle to the main PCB give it away. In order to provide you a clearer view we removed the APFC capacitors and the secondary heatsink.


As usual the transient filtering stage starts at the AC receptacle. There we find an X and two Y caps. It continues on the main PCB with an MOV, two coils and two Y caps. Although there is space on the circuit for an additional X cap, it was left vacant. In our opinion this was not a wise move since a second X cap would make a more complete transient filter.


The bridge rectifier is a BU1506 and is cooled by a dedicated heatsink which is bolted on the primary heatsink. In the APFC two STW25NM50N mosfets and a boost diode (STTH15R06D) are used to make the current waveform proportional to the mains voltage waveform. Two parallel smoothing/reservoir caps are used. They are provided by Matsushita/Panasonic (85°C, 270 µF each, 420 V) so in total the capacitance reaches 540 µF, a quite large value for the 650W of the PSU. As primary switches two SPP21N50C3 are utilized.


In the secondary side passive design is used so SBRs (Schottky Barrier Rectifiers) handle the DC outputs. The +12V output is generated by four 40CPQ060 SBRs and the minor rails by two STPS60L45CW. The presence of only two toroidal chokes indicates that the outdated group regulation design is used so the bigger choke is shared by 12V/5V and the smaller by 3.3V. All filtering capacitors in the secondary side are provided by Suscon, not the best quality choice. Since they couldn't afford Japan made at least Teapo would be greatly preferred. Finally the two heatshrinks on the fins of the secondary heatsink hide two thermistors, one for the OTP (Over Temperature Protection) and one for the fan speed control.


Housekeeping duties are performed by a PS223 IC which is one of the very few protection ICs that support OTP. An A6069H is responsible for the generation of the 5VSB and also acts as the standby PWM controller.


Soldering quality on the primary side is good enough, however on the secondary side we find several hand soldered joints and some weird connections utilizing wires. Not the best view from a quality perspective.


The cooling fan is provided by Adda, a highly respected manufacturer in its field. Its model number is AD1212HS-A71GL (Sleeve bearing, 12V, 0.44A, 2200RPM, 85.2CFM, 39.1dBA).