A Look Inside & Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the internal components of a PSU much better. Our main tool for the disassembly of the PSU is a Thermaltronics TMT-9000S soldering and rework station. It is of extreme quality and is equipped with a matching de-soldering gun. For the identification of tiny parts, we use a Andonstar HDMI Digital Microscope.


We evaluated this unit's predecessor, the SF-750F14MG, a long a time ago and are able to draw direct comparisons between the old and new Leadex platforms. A quick look shows them to nearly be identical - the only notable difference being the two bulk caps in the older SF-750F14MG since the SF-750F14EG is only equipped with one. In the primary side is the usual half-bridge topology and an LLC resonant converter, while a couple of VRMs in the secondary regulate the rails, and the electrolytic caps on the main PCB are provided by Chemi-Con.


The small PCB right behind the AC receptacle doesn't include any EMI-filtering components. The transient filter is complete, though, since we find four Y caps, two X caps, two CM chokes, and an MOV on the main PCB. There is also an NTC thermistor for protection against large inrush currents, and it is accompanied by a bypass relay.


The single bridge rectifier is a Shindengen U30K80R.


Two Infineon IPA50R140CPs are used in the APFC converter, along with a CREE C3D06065A boost diode. The older Leadex unit uses two Infineon IPP50R199CP FETs and a C3D06060A boost diode. The single bulk cap is by Chemi-Con (400 V, 470 uF, 2000 h @ 105 °C, KMQ), and its capacity looks quite low for a 750 W unit. However, the PSU does somehow manage to achieve a hold-up time above 17 ms. The SF-750F14MG uses two Chemi-Con KMR bulk caps with a combined capacity of 660 uF, which easily has it trump the new Leadex unit in this section.


The small PCB, covered by tape, most likely hosts a NCP1653A PFC controller, the same IC the old Leadex unit uses.


The primary switchers are a couple Infineon IPA50R140CP FETs configured in a half bridge topology.


This proprietary IC with markings AA9013 is the LLC resonant controller. The same IC also handles the unit's protections.


On the secondary side are six Infineon IPP041N04N Gs, there to handle the +12V rail. This task is taken care of by four Infineon IPP041N04N FETs in the older unit.


The electrolytic filtering caps on the main PCB are provided by Chemi-Con and belong to its KZE and KY lines. Several polymer caps by the same manufacturer are also used.


The DC-DC converters use eight Infineon BSC0906NS (30 V, 40 A @ 100 °C, 4.5 mΩ) FETs in total. Each VRM has its own PWM controller (NCP1587A).


Super Flower hasn't changed its 5VSB circuit from the previous Leadex platform, so we still find the usual Mospec S10C60C right next to the vertical PCB that hosts the fan controller. Besides the Mospec SBR, the 5VSB circuit also uses a PWM controller; it has the "29604" marking on it.

The fan-control board can easily snap if you try to remove the fan header, so we secured it in place with lots of glue. It uses a LM324ADG IC.



At the front of the modular board are a number of Teapo polymer and electrolytic caps for an extra ripple-filtering layer. Some might not like the use of Teapo caps too much, but we have seen other high-end PSUs using Chemi-Con KRG caps in this section, which also have a quite low lifetime. A cap's origins only tell half the story; you should look at the model number and specifications to glean all the facts.


The soldering quality is good enough, but definitely not top notch.


There are two interesting ICs on the PCB's solder side: an AX3111 step-down converter that seems to be used by the fan control circuit and an S9602 IC.


The cooling fan is by Globe Fan and uses a Fluid Dynamic Bearing, at least according to its label. Its model number is RL4Z S1352512HH, and it is a little smaller than the RL4Z S1402512HH the previous Leadex generation uses.