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!


As has already been stated, this PSU isn't made by HEC/Compucase, but is instead based on a Sirfa platform capable of up to Platinum efficiency with some component changes. The main PCB is very small, and the same goes for the heatsinks it is equipped with. A half-bridge topology with an LLC resonant converter is used in the primary side, and we come across a synchronous design with two voltage regulation modules for the generation of the minor rails in the secondary side. This is surely a modern platform, and its build quality is pretty good, especially if we take this product's price into account as Chemi-Con and Teapo filtering caps have been used and the only component that looks out of place is the cooling fan with its sleeve bearing that won't last as long as a double ball-bearing or fluid dynamic bearing. Given this PSU comes with a five year warranty and there is no semi-passive mode, which would take some of the burden off the fan, we believe that a higher quality fan should have been used.


The first part of the EMI filter is on the AC receptacle and includes two Y caps, an X cap, and an CMD02X IC that blocks current to the bleeding resistors when AC voltage is connected. The second part of the same filter is on the main PCB and uses an X and two Y caps, a CM choke, and an MOV. Unfortunately, Sirfa didn't equip this platform with an NTC thermistor and the corresponding bypass relay, so we expect inrush current to be very high. We really have to wonder why the manufacturer chose to remove such an important component since it doesn't cost much. The bypass relay isn't cheap, but one could at worst install the NTC thermistor without the relay and provide inrush current protection, at least while the PSU is cold.


The single bridge rectifier is a GBU1006. It can handle up to 10 A of current at 100 °C.


The APFC converter uses two Toshiba TK16A60N FETs and a CREE D0665C5 boost diode. The bulk cap is by Teapo, and although its capacity (560uF) looks adequate, this unit's hold-up time is lower than required.


The PFC controller is on the solder side of the main PCB; it's an Infineon ICE3PCS01G IC.


The primary switching FETs are by Infineon, and their model number is IPP50R250CP. They are arranged in a half-bridge topology, and an LLC resonant controller is there for a boost to efficiency.


The LLC resonant controller is an Infineon ICE2HS01G IC; it is installed to a vertical PCB.


The +12V rail is regulated by four Infineon IPP040N06N G FETs.


Ripple filtering on the secondary side is done through some Chemi-Con and a great number of Teapo caps. Chemi-Con KY series caps have a lifetime of up to 10,000h (depending on their size), while Teapo SCs will last anywhere from 1,000h to 3,000h at 105 °C (their lifetime is again dependent on size). Clearly, the SC caps aren't as good as the Chemi-Con KZEs, which are mostly used in mid-range and even some high-end PSUs. We believe that in a PSU that is backed by a five year warranty, higher quality caps should be used.


Since this PSU doesn't have over temperature protection, the secondary heatsink only hosts a single thermistor. It provides temperature data to the fan-control circuit.


A KIA7912PI voltage regulator generates the -12V rail.


The standby PWM controller is a Sanken STR-A6069H.


A couple DC-DC converters generate the minor rails. Both are on the same board, and a total of eight Infineon IPD060N03Ls are used, while the single PWM controller is an ANPEC APW7159.


A SITI PS223 IC handles the PSU's protections. It is among the very few supervisor ICs with support for OTP (Over Temperature Protection), which makes the fact that the GX-S550 doesn't have OTP a great shame.


Soldering quality is pretty good overall.


A low-speed Globe Fan 120mm fan is used. It uses a sleeve-bearing, which isn't suitable for PSUs where the fan is installed horizontally.


A HT772 PNP transistor by HI-SINCERITY Microelectronics is used to control the fan's voltage.