Page 3 - Physical Look - Inside
As always, we opened up our Cooler Master V850 SFX Gold 850W power supply to take a detailed look at what is going on inside. Please note that doing this will void your ten-year warranty, as there is a warranty seal on one of the screws. There are no user serviceable parts inside and opening it up may pose actual danger to the end user, so I would not recommend doing so. For the benefit of our readers, we cracked ours open to get a better look. Disassembling the Cooler Master V850 SFX Gold 850W is straightforward with the removal of four screws at the top and a few more around the unit to get underneath the PCB. The OEM for the V850 SFX Gold 850W is Gospower, which is the same OEM Cooler Master used for their MWE 650 White V2 650W. Our photo above shows an overhead view of its internal components. At first glance, the whole unit is quite tight and it was actually pretty difficult to get a better view of the internal components, but we will attempt to identify as much as we can. There are two main heatsinks inside with all the components crowded into this small space.
Starting at the transient filter stage, there is a total of two X-capacitors and four Y-capacitors near or around the AC receptacle. This is double the number recommended for both of these capacitors, which is great to see. There are also two ferrite coils and a metal-oxide varistor here. The MOV helps with suppressing voltage spikes. Found near here is also an NTC thermistor, which is used to suppress high inrush currents.
Moving inward, we are greeted with a large capacitor in black. This is a 560uF at 450V primary capacitor. Our capacitor was made by Nichicon, a reputable Japanese brand. It also has the higher 105c temperature rating, which is great to see. Cheaper power supplies may often opt for a capacitor from a lesser-known brand or one with a lower 85c temperature rating.
Continuing on, the Cooler Master V850 SFX Gold 850W uses a single rectifier bridge, but we could not identify the model of it due to its proximity to other components and the metal heatsink. The active PFC circuit in the Cooler Master V850 SFX Gold 850W is located on a silver heatsink near the primary capacitor. The active PFC circuitry is handled by two STMicroelectronics STF33N60DM2 MOSFETs. These have a drain-to-source voltage of 650V, continuous drain current of 24A at 100c, and an RDS(on) of 0.130 ohm. The main switchers can be found on the same heatsink, but I was unable to identify the models due to their proximity to the primary capacitor. These on characteristics are 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. Finally, active PFC and switching logic is controlled by a Champion CM6500UNX and Champion CM03AX.
On the secondary side, we can see electrolytic and solid capacitors rated at 105c. These are all from reputable brands like Nichicon. 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. Six NCEPower MOSFETs are responsible for generating the +12V output, located at the bottom of the PCB, not shown. Unfortunately, I was unable to find the model number for these parts, as they were rubbed off. However, they are all passively cooled with a thermal pad and a sheet of aluminum that acts as a heatsink. The +5V and +3.3V output is generated by six InPower Semiconductor IPS 014N04SA MOSFETs on a daughterboard located on the side of the power supply. ANPEC's APW7159C is the PWM switching controller. Finally, an IN1S313I-SAG 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.
From here you can get a better picture of the modular connections as well as the many more solid capacitors from Nichicon. For the most part, the internal build quality of the Cooler Master V850 SFX Gold 850W is average. It is a feat to get such power into such a small container while maintaining cooling of the components, but there are also a few unfortunate things. Soldering quality is good with no excess amounts of solder left, but there are also quite a few globs of glue internally. As mentioned previously, there are a few wires running around inside. Component selection is generally good, though some of the secondary side components are of lower quality.
As for cooling, a single 92mm, 15mm thick Hong Hua HA9215VH12FD-F00 fan. This uses fluid dynamic bearings, which should mean it can operate quietly and for longer periods of time. From the label, you can see this operates at 12V and 0.36A. Otherwise, it is connected with two wires to a daughterboard on the secondary stage of the power supply.
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion