Page 3 - Physical Look - Inside
As always, we opened up our be quiet! Power Zone 2 750W power supply to take a detailed look at what is going on inside. Please note that doing this at home may void your 10-year warranty, thanks to the warranty seal be quiet! applied over one of the attachment screws.. Either way, for the benefit of you, we cracked ours open so you do not need to. There are no user serviceable parts inside.
Disassembling the be quiet! Power Zone 2 750W was straightforward with the removal of four screws. All of the screws are hex screws, which many people do not have a screwdriver for. Of course, we have all the tools here at APH Networks. Taking out the internal components from the enclosure requires the removal of more screws, which, thankfully, are standard Philips head screws.
Our photo above shows an overhead view of its internal components. Its OEM is FSP, a reputable PSU manufacturer that also sells products under their own brand. The Power Zone 2 750W is built on the same platform as the 850W and 1000W models. It features an LLC half bridge topology with DC-to-DC converters. At first glance, the build quality appears to be excellent. There are two main heatsinks inside. All of them are painted black, located on the primary side. Additionally, there are five smaller sized heatsinks in its original aluminum finish that resides on the secondary side.
Pulling the enclosure apart, the fan was mounted over the components rather than the enclosure where the grille is, so I had to remove more screws and a bracket to get 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. be quiet!, regardless of the OEM, has done a great job in the past to make sure their power supplies met or exceeded the recommended requirements in the past, and the Power Zone 2 750W is no exception. The be quiet! Power Zone 2 750W has one metal oxide varistor, two metalized polyester X-capacitors, four ceramic Y-capacitors, and two ferrite coils This is two times the amount of X and Y capacitors than recommended.
The active PFC circuit featured on the be quiet! Power Zone 2 750W uses two Diodes Incorporated GBJ25V08 glass passivated bridge rectifiers on both sides of the black heatsink closest to the transient filter stage. At 115V, the maximum rectified forward current capacity with heatsink is 25A each, so you can theoretically pull up to 5750W (25A * 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 the fact that not every component in the system is able to keep up.
Further down the line, on the outside of the largest heatsink, we can two Magnachip IMMFT65R090RTH power transistors. Each is certified for up to 22A at 100c. These transistors present a maximum resistance of 90 mΩ and typical resistance of 79 mΩ 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. One ROHM Semiconductor SCS306AM boost diode is on the opposite side of the same heatsink. Two Infineon IPA60R180P7 MOFSETs, located right next to the boost diode, are used as the main switchers on the Power Zone 2 750W power supply. Each is certified for up to 11A at 100c, maximum resistance of 180 mΩ, and typical resistance of 145 mΩ at 25c.
Other components that can be spotted on the primary side are all located on the add-in board next to the APFC components shown in the above photo. From the left, there is a Champion CM6901T2X SLS, SRC/LLC + SR resonant controller, Novosense NSi6602 dual channel gate driver IC, and a Champion CM6500UNX active PFC controller.
On the primary side, we can see two Taiwanese brand Elite capacitors. Japanese brand capacitors are preferred. Our 750W version of be quiet!'s Power Zone 2 series power supply incorporates two capacitors, both 270µF x 420V, in parallel for a total of 540µF capacitance. They are rated at 105c, whereas more value-oriented power supplies usually use 85c rated capacitors.
On the secondary side, we can see more Elite capacitors rated at 105c. 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 PSMN1R4-40YLD power MOSFETs are responsible for generating the +12V output, located at the bottom of the main PCB. The PSMN1R4-40YLD's rated continuous drain current is 240A at 10V, 25c. It has an RDS(on) value of 1.4 mΩ maximum and 1.12 mΩ typical at 10V, 25c.
Four Magnachip MDU1513 MOSFETs are responsible for generating the +5V and +3.3V outputs, located on the vertical board perpendicular to the rear connector board. The MDU1513's rated continuous drain current is 70.4A at 70c. It has an RDS(on) value of 4.6 mΩ maximum and 4.0 mΩ typical. An uPI Semiconductor uP3861P dual channel synchronous rectified buck controller and Weltrend WT7527RA monitoring IC for over/under current and over/under voltage protection can be seen on the same board as well. The datasheets for all components mentioned in this review can be found on their respective manufacturer's websites.
At the very back, we have a large daughterboard covering the entire rear panel for the modular cable sockets. All connection points are soldered directly to the add-on PCB after the secondary stage to reduce power transmission loss compared to having wires. The output connector configuration can be seen on the previous page.
Overall, the internal build quality of be quiet!'s Power Zone 2 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 quite clean in general. I would say the be quiet! Power Zone 2 750W is generally good with regards to the selection of components used under the hood, appropriate for its price and performance class.
Lastly, we see a 140mm fan that provides cooling to the be quiet! Power Zone 2 750W's internal components. It is connected to the controller using a 2-pin connector. A 140mm fan is the largest you can fit in an ATX power supply, and it is beneficial in most cases in providing lots of airflow at lower speeds for quiet operation.
The fan is a be quiet! Pure Wings 3 PUW3-14025-HR, as shown in our photo above. The Pure Wings 3 PUW3-14025-HR is a rifle bearing fan with a 4-pole fan motor specified at 0.42A for a maximum of speed of 1800 RPM. Other specifications include 30.5 dBA noise level, 72.2 CFM airflow, and 2.44 mmH2O air pressure. The fan is not supposed to activate until the PSU is loaded up. As such, it should remain off during normal operation, and even when it is on, be quiet! uses a silent speed profile, so noise is not going to be a problem at all. Fans with rifle 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
