Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the insides of a PSU better.



This is a new platform by Helly Technology, or the first time I have come across it. The heatsinks are small on both the primary and secondary sides, and both VRMs and the fan-control circuit are installed on a daughter-board to save space. Airflow will be good since no cables are disrupting it, and the distance between parts is good as well, especially if we take into account the tiny dimensions of the main PCB. Helly used decent parts—the only exception is the Yate Loon fan. I am not that fond of this brand when it comes to fans because they allow tooling to grow too old before replacing it, which results in high production tolerances with units produced with said tooling.


The transient/EMI filter stages have all the necessary parts.


I found a TRX NB210108 SMD-Y-CAP on the business side of the main PCB.


The MOV is not covered in heat shrink, so you will find parts of it everywhere inside the PSU if it blows. Moreover, there is no inrush protection, which is a shame for a product that wants to compete with the high-end offerings in the 750 W SFX category.


The single bridge rectifier is bolted to a small heatsink. Lian Li should ask for a larger heatsink.


The APFC converter uses two Oriental Semiconductor FETs and a Global Power Technology boost diode. The bulk cap is by Chemi-Con and doesn't have enough capacity to provide a hold-up time of over 17 ms.


The APFC controller is a Champion CM6502UHH.


The main FETs are by Oriental Semiconductor and installed in a half-bridge topology.


The LLC resonant controller is a Champion CU6901T2X. The second photo above depicts the resonant tank.


The unit's main transformer is semi-surrounded by a metallic shield also acting as a heatsink.


The FETs regulatimg the +12 V rail are installed on the solder side of the main PCB.


Two DC-DC converters generate the minor rails. They are installed on a daughter-board that also hosts the fan's header.

They use six Infineon FETs, and their joint PWM controller is an Anpec APW7159C. I also found the supervisor IC, a Weltrend WT7527RA, on the same board as the VRMs.


There aren't many electrolytic caps since Helly mostly used polymer ones. That having been said, the few electrolytic caps Helly uses are high-quality Chemi-Con caps from good lines.


The 5VSB circuit uses an EM8569C PWM controller.


The supervisor IC is a Grenergy GR8313, which only provides the essential protection features.


Several polymer caps are installed on the face of the modular PCB.


Soldering quality is decent; not the best I have seen, it is not bad, either.


The cooling fan is by Yate Loon and not of good quality. They should go with a Globe Fan for a double ball bearing, or an FDB by Hong Hua to keep the cost low but still offer a good fan.