Disassembly
The input filtering consists of one coil, two Y capacitors and one MOV. There is not an X capacitor to be seen (the red film capacitor is not part of the input filtering, but is actually on the PFC circuit). This is fewer components than recommended – there should be an extra coil and two X capacitors. The PFC section uses a single Infineon SPA11N60C3 transistor and a 220µF Capacitor made by Yang Chun. The transistor is rated for 11A at 25°C (and 7A at 100°C) with an RDS-on of 0.38Ω. The switching transistors are Alpha and Omega AOT8N50s in a two-transistor forward configuration, which are rated for 8A at 25°C (and 6A at 100°C) with an RDS-on of 0.85Ω. The primary side is controlled by a Champion CM6806 PFC/PWM controller combo IC.
All of the capacitors in this power supply are made by Yang Chun – a Chinese brand which I have had mixed experiences with. I’ve seen plenty of them fail after little more than 3 years, and I’ve also seen a few last longer than that. One problem in this power supply is that one of the 5vsb filtering capacitors is touching the heatsink tab on the 5vsb rectifier diode – meaning that it will be getting heated up by it whenever the power supply is plugged in. I really don’t have high hopes for that capacitor.
The 12V rail uses synchronous rectification to achieve higher efficiency. The transistors used are four Alpha and Omega AOT260Ls. They are rated for 140A at 25°C and 110A at 100°C, with an RDS-on of 0.0029Ω. This is plenty of capacity for a 550W unit. The other two rails use DC-DC conversion from the 12V rail. The VRMs use two AOD508 transistors, which are rated for 70A at 25°C and 55A at 100°C with an RDS-on of 0.0045Ω. Again, plenty of capacity for 24A rails. They are controlled by an Anpec APW7073 controller IC. The main secondary controller IC is a Grenergy GR8313. It doesn’t support Over Current Protection, so this is a single rail product.
The soldering is pretty good on this power supply. There are a few hand-done joints, but none of them are overly messy (with the exception of the 12V wires). There are no loose solder blobs, all of the legs are cut to appropriate lengths, and the joints all have an appropriate amount of solder.
The fan is made by Shenzhen Huaxinrong Plastic Electronic Co. I have never heard of this brand before, and the website printed on the sticker doesn’t contain any information on its specifications. It appears to be a sleeve bearing part. There is enough oil in the bearing, but one small problem is that the plug doesn’t have a particularly good seal, and oil was leaking out of it when I peeled the sticker off. At least this shouldn’t be too much of a problem as long as the sticker stays on. The fan was very quiet at first, and only began to speed up at 250W load. Even at full load, though, it wasn’t loud enough to be really annoying. The heat sinks are fairly small for a 550W product. I do wonder if larger heat sinks would have been all that was needed in order to keep the efficiency up at higher loads.
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