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. With such equipment in hand, breaking apart every PSU is like a walk in the park!
This unit, like all Fortress units, is by ATNG, a pretty good OEM with some high-performance platforms in its arsenal. The only weird and rather annoying thing about these guys, to reviewers, is that they erase all markings on their components, which makes it seem as though ATNG purposefully goes out of its way to hide their origin. We find it pretty strange and have to wonder. The Fortress-750 uses an LLC resonant converter in its primary side for increased efficiency, and two DC-DC converters in the secondary side to generate the minor rails. Mosfets in the secondary side also regulate the +12V rail. This is, in other words, a typical, good Platinum implementation with several good (Chemi-Con) and decent quality caps (Teapo).
Behind the AC receptacle is a small PCB with three X and four Y cap and a CM choke. The transient filter's other components are on the main PCB and consist of two Y and two X caps, a CM choke, and an MOV, right behind the bridge rectifiers.
The two bridge rectifiers are by Shindengen, and their model number is U15K80R. They can handle up to 30 A combined, which is more than enough to cover the needs of this PSU.
In the APFC, a single Infineon IPW60R099C6 fet is used, and two diodes (CREE C3D06060A) boost the pulsating rectified mains up to a loosely regulated bus voltage of around 380 V DC. The two hold-up caps are by Nippon Chemi-Con (400 V, 220 µF each or 440 μF combined, 105°C, KMM series).
As main switches, two Infineon IPW60R190C6 fets are used. We don't know which LLC resonant controller this unit utilizes, and the same goes for its APFC controller.
The standby PWM controller had its markings erased, but we are pretty sure it belongs to the STR-A6000 family.
Four Infineon IPP023N04N fets handle the +12V rail in the secondary side. Moreover, two DC-DC converters generate the minor rails off the +12V rail. Each VRM also has a dedicated PWM controller and two fets. As ATNG does, all markings on the aforementioned controllers and fets were carefully erased.
The thermistor used by the fan-control circuit, attached to the secondary heatsink.
Few polymer and enough electrolytic caps, by Teapo, are used in the secondary side, along with several electrolytic Chemi-Con caps. We would definitely prefer all of them to be by Chemi-Cons, but cost was apparently a big factor. Yet, considered among the best non-Japanese caps available today, Teapo caps are of decent quality.
Soldering quality has improved immensely over the Fortress-550 we already reviewed, and we can safely say that it is more than descent now. The soldering side also holds the protection IC responsible for all housekeeping duties. A GR8313, also shown in the last of the above photographs, it only offers the very basic protections.
The cooling fan is by Globe Fan, and its model number is RL4Z B1352512H (12 V, 0.3 A). It uses double ball-bearings, which will have it last for a long time. It has eleven blades, and a plastic baffle is used to direct its airflow toward the rear the PSU.