FSP Dagger Pro 850W Report (Page 3 of 4)

Page 3 - Physical Look - Inside

To begin our internal inspection of the FSP Dagger Pro 850W, I opened the PSU. Please note doing this at home may void your 10-year warranty thanks to a seal that extends over one edge of the power supply. But for your benefit, I disassembled mine, so you do not need to. There are no user-serviceable parts inside.

Taking apart the FSP Dagger Pro 850W is quite straightforward with the removal of four screws next to the fan mount. The photo above shows an overhead view of its internal components. The OEM is FSP itself, which is not a surprise. At first glance, the build quality appears to be reasonable. There are two main heatsinks inside, both with a silver color scheme. As this is an SFX PSU, it is also no surprise that all the components are squeezed in together. Nonetheless, on to our internal inspection.

Starting with the transient filter stage, we find ourselves with a single metalized polyester X-capacitor and two ceramic Y-capacitors at the AC receptacle with another X-capacitor on the mainboard. This is two times the number of X capacitors than recommended, which is always nice to see. Three ferrite coils and one metal oxide varistor or MOV are also located at the transient filter stage of this supply. It is also great to see the MOV, which is used to protect the power supply from AC voltage spikes. Not all modern power supply units have one, so it is good to spot one here.

On the primary side, we can see one Japanese-made Nippon Chemi-Con and two United Chemi Con capacitors. 100% Japanese-made capacitors are one of the main selling points of the FSP Dagger Pro 850W, so this is a good start. Our 850W version of the Dagger Pro series power supply incorporates one 120μF x 420V and two 150 μF x 420V capacitors for a total of 420 μF. All capacitors are rated at 105 degrees Celsius, which is much better than the more value-oriented 85 degrees Celsius rated capacitors out there.

The active power factor correction or APFC circuit uses two HY GBU1506U rectifier bridge attached to the first heatsink. At 115V, it has a rated current of 15A at 100 degrees Celsius, so you can theoretically pull 3450W (15A * 115V * two diodes). This, of course, is limited to the fact that it is not 100% efficient, just like any electrical component or device. This also neglects the fact that other components are unable to keep up. Either way, this far exceeds the 850W this power supply unit is rated for.

Moving forward, we have two Infineon IPW60R120P7 power transistors directly attached to the largest heatsink. Each is certified for up to 16A at 100c. These devices have a typical RDS(on) value of 100mΩ and a maximum of 120mΩ. It is important to note that the lower the Static Drain-Source On-Resistance on these transistors are the more efficient these components will be. This is because the Static Drain-Source On-Resistance, or RDS(on), will dissipate power, so the smaller the resistance, the less power wasted. Two STMicroelectronics STPSC8H065 Schottky diodes are the boost diodes on the active PFC circuit. Two Infineon IPA80R310CE transistors are located on the smaller heatsink, which are responsible for the main switching. The continuous drain current for these devices is 10.6A at 100 degrees Celsius. The typical RDS(on) value is 250mΩ and the maximum RDS(on) value is 310mΩ at 25 degrees Celsius. Another important component to note is the Diode Incorporated S5MC surface mount glass passivated rectifier. Finally, the switching logic and APFC are controlled by an FSP 6601 IC, like how the 650W version had its own FSP 6600 IC.

On the secondary side, we have a collection of smaller capacitors all rated at 105 degrees Celsius. There is a mix of Nippon Chemi-Con and Rubycon capacitors here, which are both Japanese brands, living up to their claim of 100% Japanese-made capacitors. Six Toshiba TPH1R306PL Silicon N-channel MOSFET transistors are located at the bottom of the mainboard, which are responsible for generating the +12V output. The continuous drain current for these devices is 100A at 25 degrees Celsius and a drain-source voltage of 60V. The typical RDS(on) value is 1.0mΩ and the maximum RDS(on) value is 1.34mΩ. On the daughterboard, we have four Infineon BSC0902NS transistors responsible for generating the +5V and +3.3V outputs. The continuous drain current for these devices is 67A at 100 degrees Celsius and the drain-source voltage is 30V. The typical RDS(on) value is 2.2mΩ and the maximum RDS(on) value is 2.6mΩ. A PFC Device Corporation PT20L80E Schottky Rectifier is located at the bottom of the board, not visible in the photo. An ANPEC APW7159C PWM controller is located on the daughterboard. Finally, we can also have an EA152 IC chip, which is responsible for overvoltage, overcurrent, overheat, and short circuit protection. The datasheet for all the components mentioned is found on their respective manufacturer’s websites.

Since this is a fully modular power supply, we have a large daughterboard at the output side for the modular cable connections. All connectors at the bottom of the daughterboard are soldered directly to the main PCB after the secondary stage to reduce power transmission loss. The output connector configuration is shown on the previous page. Overall, the internal build quality of FSP’s Dagger Pro 850W is very good. Aside from a few glue glops, which is normal, the components are arranged very cleanly for optimal cooling with practically no wires running around inside. The solder points on its black PCB are acceptably clean in general. I would say the FSP Dagger Pro 850W is generally good with regards to the selection of components used under the hood, appropriate for its performance class.

In terms of cooling performance, there are two things we need to pay attention to for a power supply unit; namely the heatsinks and cooling fan. In this case, we can see multiple heatsinks and one cooling fan inside FSP’s Dagger Pro 850W. The layout of heatsinks inside the SFX power supply unit is well-thought-out to fit into such a tiny enclosure. The OEM of the fan is Power Logic, with PLA09215B12H as the model number. This is the same fan used in the 650W version. The size of the fan is 92mm in diameter, which is the maximum the enclosure can accommodate. Further research indicates the PLA09215B12H is a ball-bearing fan that runs at a current of 0.55A. Ball-bearing fans are generally more reliable than sleeve bearing fans, although this comes at the cost of more noise. However, the FSP Dagger Pro 850W is a semi-fanless PSU, meaning the fan will only operate when there is enough load.


Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion