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. With such equipment in hand, breaking apart every PSU is like a walk in the park!


The unit is not made by Enermax, but by Channel Well Technology (CWT), a well-respected manufacturer. The design is rather conservative to keep the cost as low as possible, and the main PCB is quite small. The primary side probably uses a double forward topology, and we meet passive rectification along with a group-regulated scheme in the secondary side, where the +12V and 5V rails are regulated by the same circuit; the 3.3V is regulated separately. We also had to remove some components to clear the view to crucial parts.


A small daughter-board houses all the components of the first part of the transient filtering stage: two Y caps, a single X cap, and a CAP004DG discharge IC. The second part of the transient filter is on the main PCB, with one X and two Y caps, two CM chokes, one DM choke, and an MOV. Another Power Integrations CAP004DG IC has also been installed onto the solder side of the PCB, right below the X cap.


The bridge rectifier is a GBU1506. It is cooled by a dedicated heatsink.


In the APFC, two Fairchild FCPF20N60 fets are used along with an 8S2TH061 boost diode. The hold-up cap is provided by Nippon Chemi-Con (400 V, 390 μF, 105 °C, KMR series), and the combo PFC/PWM controller is the in similarly efficient PSUs omnipresent Champion CM6800TX IC. The aforementioned IC is supported by a CM03X Green PFC controller, which improves the IC's efficiency. This is very good news; we didn't expect the presence of the CM03X IC in a Bronze efficiency unit.


Two Toshiba K20A60U fets are used as main switchers.


Passive rectification is used in the secondary side. Only two toroidal chokes indicate that a group regulation scheme is being utilized. The +12V rail is rectified by four PFR40V60CT SBRs (Schottky Barrier Diodes). The 5V rail is being rectified by a single PFR30L30CT, and 3.3V is being rectified by an STPS30L45 SBR.


CWT apparently used the cheapest capacitors they could find in the secondary side, since we discovered AiSHi and CapXon caps there. Definitely not an ideal choice, even for a mainstream/middle-end unit, since the capacitors of the secondary side are of great importance and don't, on top of that, have an easy life. They get hot due to ripple filtering and their cooling is not ideal because of the cables that surround them. The specified caps are at least rated at 105°C, but we would definitely prefer Japanese caps, even if they were only rated at 85°C.


The standby PWM controller is a TNY177PN IC.


The supervisor IC, a Sitronix ST95313, is backed up by an LM393 voltage comparator, with the latter having been soldered onto the rear side of the main PCB. Very briefly: a comparator is a device that compares two voltages or currents and provides an indication of which is higher. They are mostly used by OCP (Over Current Protection) circuits, but can be also used by many other circuits in a PSU.


Soldering quality on the main PCB is quite good, something typical for a CWT product. Thankfully, no compromises were made in this area.


The cooling fan is equipped with ball-bearings and will, as such, last much longer than a sleeved-bearing fan. It is provided by Yate Loon Electronics, and its model number is D12BH-12 (12 V, 0.3 A, 2300 RPM, 89 CFM, 41 dBA). It is, generally speaking, good but noisy at high fan speeds. Here we should note that exactly the same fan is used in Corsair's ultra-high-end AX760i and AX860i PSUs, so you can brag to yourself about the PSU using the same fan as the one in Corsair's top dogs!