Page 3 - Physical Look - Inside
As always, we opened up our Corsair CX750F RGB 750W power supply to take a detailed look at what is going on inside. Please note that doing this at home may void your 5-year warranty thanks to a seal that extends over one edge of the power supply. But for the benefit of you, we cracked ours open so you do not need to, haha. There are no user serviceable parts inside.
Disassembling the Corsair CX750F RGB 750W is quite straightforward with the removal of four screws behind the labels on the side. Our photo above shows an overhead view of its internal components. Its OEM is HEC, a manufacturer of mostly budget products since 1979. At first glance, the build quality appears to be very good. There are four main heatsinks inside. The two larger ones painted black are located on the primary side, while two smaller sized heatsinks reside on the secondary side.
Pulling the enclosure apart, and we got straight to the internal inspection. The transient filter stage is the first input stage of a computer power supply, so we will take a look at that first. Corsair, regardless of the OEM, has always done a great job in the past to make sure their power supplies met or exceeded the recommended requirements, and the CX750F RGB 750W is no exception. The Corsair CX750F RGB 750W has one metal oxide varistor, three metalized polyester X-capacitors, four ceramic Y-capacitors, and two chokes. This is three times the amount of X capacitors and twice the amount of Y capacitors than recommended.
On the primary side, we can see one Japanese-made Hitachi capacitor. 100% Japanese-made capacitors are not specified on the marketing material, and as you will see, this is one of the three Japanese-made capacitors in this power supply. Our 750W version of Corsair's CX-F RGB series power supply incorporates one 470µF x 400V capacitor. It is rated at 105c; whereas more value-oriented power supplies usually use 85c rated capacitors.
The active PFC circuit featured on the Corsair CX750F RGB 750W uses two Won-Top Electronics GBU15K bridge rectifiers attached to opposite sides of the first heatsink. At 115V, the maximum rectified forward current capacity with heatsink is 15A each, so you can theoretically pull up to 3450W (15A * 2 diodes * 115V) from the bridge rectifier at 100% efficiency. Of course, this is limited by the fact that it is not 100% efficient, and also neglects not every component in the system are able to keep up. Further down the line, on the outside of the largest heatsink, we can see two Infineon IPA60R120P7 power transistors. Each is certified for up to 16A at 100c. These transistors present a maximum resistance of 0.120 ohm when turned on according to the manufacturer's data sheet. This on characteristic is called Static Drain-Source On-Resistance, or commonly abbreviated as RDS(on). The more efficient the component is, the lower the RDS(on) value, since it wastes less power with lower resistance. An Infineon IDH06G65C6 boost diode is placed right next them. Two Alpha & Omega Semiconductor AOTF22N50 power MOFSET transistors, located on the smaller heatsink between the main capacitor and transformer, are used as the main switchers on the CX750F RGB 750W power supply. Each is certified for up to 15A at 100c and maximum resistance of 0.26 ohm.
Other components that can be spotted on the primary side include a Champion CM6500UNX PFC controller, CM03X phantom power remover, and a Monolithic Power Systems HR1001C active PFC controller at the bottom.
On the secondary side, we can see more capacitors rated at 105c. However, besides two United Chemi-Con, the rest are all Teapo. All rectifiers produce the +12V out, while the +5V and +3.3V outputs are generated from the +12V output using a DC to DC converter within as with modern high efficiency power supplies. Four Nexperia PSMN2R6-40YS MOSFETs are responsible for generating the +12V output, located at the bottom of the PCB, not shown. The PSMN2R6-40YS's rated continuous drain current is 100A at 100c. It has an RDS(on) value of 0.0028 ohm maximum and 0.0020 ohm typical at 25c. Four Potens Semiconductor PDD3906 MOSFETs on each of the two add-in boards, for a total of eight, generate the +5V and +3.3V output from the +12V rail. The PDD3906's rated continuous drain current is 51A at 100c. It has an RDS(on) value of 0.006 ohm maximum and 0.0048 ohm typical. ANPEC's APW7073 is the PWM switching controller; one on each add-in board for a total of two. Meanwhile, a Weltrend WT7527 monitoring IC provides over current and over/under voltage protection. The datasheets for all components mentioned in this review can be found on their respective manufacturer's websites.
Other components that can be spotted include an STC 15W408AS microcontroller, KEC KIA7912PI for the -12V circuit, and an Infineon BSC0906NS MOSFETs for the +5VSB line.
At the back, we have a relatively small daughterboard covering approximately half the rear panel for the modular cable sockets. All modular sockets at the bottom are soldered directly to the main PCB after the secondary stage to reduce power transmission loss. The output connector configuration can be seen on the previous page. Overall, the internal build quality of Corsair's CX750F RGB 750W is very good. Components are arranged very well for optimal cooling with practically no wires running around inside, and solder points on its black PCB is acceptably clean in general. I would say the Corsair CX750F RGB 750W is generally good with regards to the selection of components used under the hood; appropriate for its performance class.
Lastly, we see a 120mm fan that provides cooling to the Corsair CX750F RGB 750W's internal components. It is connected to an add-in board using a 7-pin connector for its RGB lighting and fan speed control. A 120mm fan is rather small nowadays for a power supply with a bottom mounted fan, but if not a lot of heat is being generated, it should not be much of an issue. The fan is a Corsair NR120L RGB, as shown in our photo above. The NR120L has eight individually addressable RGB LEDs and is a rifle bearing fan specified at 0.22A. Its maximum rotational speed is 2200 RPM.
The addressable RGB LEDs can be controlled by pressing the button at the back, using the separately purchased Corsair iCUE RGB Lighting Controller, or your motherboard’s built-in ARGB controller with the included adapter cable.
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion