Page 3 - Physical Look - Inside
As always, we opened up our Cooler Master V750 750W power supply to take a detailed look at what is going on inside. Please note that doing this at home will void your five year warranty, thanks to the warranty seal Cooler Master applied over one of the attachment screws. 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 Cooler Master V750 750W is quite straightforward, with the removal of four screws. Unlike the Seasonic-based Cooler Master V1000 1000W, the V750 750W's OEM is Enhance, a well-regarded manufacturer since 1986. Our photo above shows an overhead view of its internal components. At first glance, the build quality appears to be excellent, as one would expect from the company. There are three main heatsinks inside. One large one is located on the primary side, while a couple of adjoining small heatsinks reside on the secondary side, all of which are unpainted.
A quick tug on the shell, 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. Cooler Master has always done a great job in the past to make sure their power supplies met or exceeded the recommended requirements, and the Enhance based V750 is no exception. The Cooler Master V750 750W has two ferrite coils, one metal oxide varistor, three metalized polyester X-capacitors, and four ceramic Y-capacitors. This is three times the amount of X capacitors and two times the amount of Y capacitors than recommended. Considering how many modern day PSUs have missing MOVs, I am happy to see it here, as this component is used to stabilize spikes from the AC line. A Sanken A6069H current mode control PWM regulator IC for controlling standby power can be spotted as well.
On the primary side, we can see one Japanese brand Nippon Chemi-Con capacitor. Japanese brand capacitors are usually what we expect from something in this price range, so this is nothing surprising. Our 750W version of Cooler Master's V series incorporates one 560µF x 450V capacitor. This unit is rated at 105c; whereas more value oriented power supplies usually use 85c rated capacitors.
The active PFC circuit featured on the Cooler Master V750 750W uses one Diodes Incorporated GBU1006 glass passivated bridge rectifier attached to one side of the larger heatsink. At 115V, the maximum rectified forward current capacity with heatsink is 10A, so you can theoretically pull up to 1150W (10A * 1 diode * 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 the fact that not every component in the system are able to keep up. Two Magnachip MMF60R190P N-channel MOSFETs are used on the active PFC circuit on the Cooler Master V750 power supply, with a STMicroelectronics STTH12R06 power diode. This rectifier is certified for up to 12A at 125c. Four Infineon IPP50R280CE power MOFSET transistors can also be found on the same aluminum heatsink, with a Champion CM6901 LLC resonant controller and CM6502 PFC controller to boost efficiency. Each Magnachip MMF60R190P MOFSET can deliver up to 12.7A at 100 degrees Celsius continuously. These transistors present a maximum resistance of 0.19 ohm when turned on; with a typical resistance of 0.17 ohm according to the manufacturer's data sheet. The Infineon IPP50R280CE MOSFETs can deliver up to 8.2A at 100 degrees Celsius continuously; with a maximum resistance of 0.28 ohm, and a typical resistance of 0.25 ohm. 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.
On the secondary side, we can see more Japanese brand capacitors from Nippon Chemi-Con and Rubycon rated at 105c. As with modern high efficiency power supplies, all rectifiers produces the +12V out -- while the +5V and +3.3V outputs are generated from the +12V output using a DC to DC converter within the power supply unit. Four Infineon IPP023N04N MOSFETs on the smaller black heatsink are responsible for the rectification process. The IPP023N04N's rated continuous drain current is 90A at 100c, and a pulsed drain current of 400A. Drain source voltage is rated at 40V, and a RDS(on) value of 0.0023 ohm maximum and 0.0019 ohm typical. In the middle are two add-in printed circuit boards, each with one ANPEC APW7073 synchronous buck PWM controller and one Infineon BSC050NE2LS power transistor. The BSC050NE2LS's rated continuous drain current is 37A at 100c, and a pulsed drain current of 232A. Drain source voltage is rated at 25V, and a RDS(on) value of 0.0071 ohm maximum and 0.0057 ohm typical. One PFC Device Corporation PFR10V45CT MOS Schottky rectifier can be seen near the two add-in PCBs. A Sanken A6069H current mode control PWM regulator IC for controlling standby power can be spotted as well. Meanwhile, a Silicon Touch PS223 monitoring IC provides the V750 750W's OVP, UVP, and OCP protection. The datasheets for all components mentioned in this review can be found on their respective manufacturer's websites.
At the back, we have a large daughterboard covering the entire rear panel for the modular cable sockets. There is nothing special going on here electrically; all sockets are connected to the main circuit board after the secondary stage cleanly by an add-on PCB. The output connector configuration can be seen on the previous page. Overall, the internal build quality of Cooler Master's V750 750W power supply is excellent -- something we would expect from what we have seen from the company in the past. Components are arranged pretty well for optimal cooling with minimal wires running around inside, and solder points on its red PCB is quite clean in general. I would say the Cooler Master branded, Enhance built V750 is generally very good with regards to the selection of components used under the hood.
Lastly, we see a 120mm fan that provides cooling to the Cooler Master V750 750W's internal components. It is connected to the mainboard using a 2-pin connector. 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 V750 is not a semi-passive power supply. A 120mm fan is used to keep the enclosure as small as possible, considering the V750 is only 140mm deep. Cooler Master installed their own fan, with Silencio FP A12025-25RB-2IN-F1 as the model number, as shown in our photo above. It comes from the same product line as the Cooler Master Silencio FP 120 PWM Performance Edition my colleague Aaron Lai covered back in March. Further research indicates the A12025-25RB-2IN-F1 is a fluid dynamic bearing fan specified at 0.16A for a maximum of speed of 2250 rpm. Fans with fluid dynamic bearings generally have much longer lifespans compared to sleeve bearing fans, and is quite suitable for this application.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
