Dissection and Inspection (Part I)

Disclaimer: Power supplies can have dangerous voltages inside them even after being unplugged, DO NOT OPEN POWER SUPPLIES. It’s just not a good idea, and doing so could very well kill you. Don’t try this at home. Don’t try this at work. Just don’t do it.

If the concept of a sudden shocking convulsive death isn't enough to keep you out of your PSU, there is this character too:

There's a screw under there and there is no way the sticker comes off without dying in the process. If it dies, so does your five year warranty!

Admittedly that stopped me only long enough to pull the sticker off (in about five million pieces), but that's me and I still don't recommend opening PSUs.

First up is the fan as it is the first thing I have to remove. It is a Hong Hua model, plenty powerful too. Interestingly its label is printed in English and German of all things, not what you usually see coming from a company name like Hong Hua. Regardless, it's a nice fan. Still no switch for the LEDs though.

Now we can see the guts of the PSU:

Pulling the PCB out and flipping it reveals the soldering:

Not quite enough solder there. Clearly enough for functioning as I take the unit apart after testing, but more would be better. There is a UL listing number on the board that belongs to HUIZHOU HOSOND PCB CO LTD, whoever that is. The number on the PSU's case belongs to OCZ.

Other than the soldering issue above things look good on the main PCB, there aren't any long leads in danger of shorting out, nor do I see any other issues.

From this point we'll follow the power through the unit, pretending for a bit that "power" actually exists as such and that it flows through the unit. The reality is an absolutely fascinating mess of electrical theory that is well beyond the scope of this review. If you don't want to pretend that's fine too, we're starting with the transient filter anyway.

The transient filter's job is to clean up the incoming AC power and remove any brief spikes in it, these spikes can be caused by radio transmissions, fluorescent lights, computer power supplies and many other things. As usual the filter starts at the receptacle, in this case with two Y capacitors and an X capacitor.

Decent soldering here. Also note the resistor to dump the charge in the capacitors so you don't blast yourself with voltage stored in the capacitors after unplugging the unit. The PCB has more transient filter.

A fuse, a TVS diode (for surge protection), two Y capacitors, two inductors and another X capacitor round out the transient filter. It isn't the most overkill I have seen, but it's solid enough.

After the power is clean it passes on to the rectifiers, there are two of them bolted to a heatsink with additional plates on both sides. Unfortunately this makes them impossible to check for parts numbers without a full disassembly and my desoldering setup is not up to a 1000W PSU. The rectifiers remain a mystery. After the rectifiers there is another X capacitor to clean up the noise caused by the diodes in the rectifiers switching.

Once rectified and re-cleaned the APFC unit takes over, it boosts the voltage to the high 300s and stores it in a pair of large Japanese 105c rated capacitors.

To do this it uses a pair of 35N60C3 MOSFETs rated at 21 amps at 100c (and 34 at 25c) and 650 volts for switching, and a pair of CREE C3D06060 diodes rated at 6 amps and 600 volts. The MOSFETs are wired in parallel, as are the diodes. The first picture is of the switches, second is of the diodes, third is of the storage caps. Also visible in picture #2 is the inrush protection thermistor and the relay that shorts it for improved efficiency once the unit is running.

The brains of the PFC as well as the secondary PWM are housed in this character:

Now that we have 300odd volts to play with it heads to the main switches. There are two main switches, both are 35N60C3 MOSFETs just like the APFC switches.

For rectification on the secondary side we have seven 037N08N MOSFETs rated at 80 volts and 100 amps (that's at 25c AND 100c!). 700 amps of rectification is my kind of overkill.

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