Dis-assembly
Starting as usual at the input filtering, the Megapower Elite 550 contains three X capacitors, two coils, four Y capacitors, and an MOV, which is more than good enough. The Active PFC section only uses one STP10MK60Z transistor rated at 10A, with a 150µF capacitor from Teapo. I have to admit that it does seem a bit undersized, considering how many power supplies use two transistors and at least a 220µF capacitor. Another two STP10MK60Zs are used as the switching transistors in two transistor forward topology. They are controlled by a Champion Micro CM6805A PFC/PWM Controller combo IC.
The capacitors used on the secondary side are all made by Teapo. They are about as good as Taiwanese capacitors get, but are still far less reliable than their Japanese counterparts. Considering the corners cut on the primary side, though, they come as no real surprise.
The 12V rail has two Taiwan Semiconductors MBR30L60CT Schottky rectifiers rated at 30A each. The other two rails use a single MOSPEC S30D45C Schottky rectifier, which is also rated at 30A. This gives us a maximum theoretical current of 60A for the 12V rail and 30A for the 5V and 3.3V rails. The secondary side is monitored by a Hawyang HY-510N supervisor IC. The only protections supported are under-voltage and over-voltage protections. It doesn’t support OCP to separate the 12V rails, so this is a single rail power supply.
Like on my last Sirfa built power supply (the OCZ ZS series 650), the soldering is fairly tidy, with my only complaints being a few long component legs. All of the joints have enough solder, and there are no excess blobs.
The fan is made by Globe Fan. This model is rated for a top speed of 1500RPM, with noise and airflow ratings of 29.2dBA and 106.86CFM respectively. It remained almost silent throughout the testing. The heat sinks are rather small, which isn’t good when the fan runs as slow as it does. The plastic washer on the PFC diode looks like it has started to melt, which is an indication that the heat sinks are too small and weren’t dissipating enough heat.