After our basic load tests we tried to pull even more power from Kingwin ABT-450MM keeping it working inside its specs.
Starting from test number six presented in the previous page, we started increasing +12 V currents as much as we could. Configuring our load tester to pull 20 A at each one of its +12 V inputs the power supply wouldn’t turn on, showing us that OPP (Over Power Protection) was in action – which is great.
From there we configured our load tester to pull 20 A from its +12V1 input and 19 A from its +12V2 input and the power supply worked fine for a few minutes, and then silently died. When we disassembled the power supply we tested all major components and none of them were burned – only the fuse. We replaced the fuse (a 7 A slow burn fuse) and the power supply was back to life!
After resurrecting our power supply we configured our tester to pull 19 A from each 12 V input and the power supply worked just fine at a room temperature of 50º C. The complete results from this test can be seen below.
Input | Maximum |
+12V1 | 19 A (216 W) |
+12V2 | 19 A (216 W) |
+5V | 6 A (30 W) |
+3.3 V | 6 A (19.8 W) |
+5VSB | 3 A (15 W) |
-12 V | 0.5 A (6 W) |
Total | 515 W |
% Max Load | 114.4% |
AC Power | 705 W |
Efficiency | 73.0% |
So basically this power supply over power protection is set a little bit higher from where it should be configured. Anyway, even though this power supply died during our overload tests, we could easily bring it back to life by replacing its fuse. The problem is that replacing a fuse inside a computer power supply is a very complicated process for a regular user, as on this power supply the fuse is soldered directly on the printed circuit board and not installed using a fuse holder.
Noise and ripple was, once again, inside specs, at 29 mV on the +12V1 input from our load tester, 30.4 mV at +12V2 input, 17.6 mV at +5 V and 15.6 mV at +3.3 V. These values are peak-to-peak voltages and can be seen on the figures below.
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Figure 16: Noise and ripple at +12V1 input from our load tester.
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Figure 17: Noise and ripple at +12V2 input from our load tester.
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Figure 18: Noise and ripple at +5V input from our load tester.
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Figure 19: Noise and ripple at +3.3V input from our load tester.
We tested over current protection (OCP) by leaving only the main motherboard connector installed on our load tester and configuring it to pull 28 A from the power supply. Since the power supply worked just fine, we can assume that this power supply doesn’t have an OCP circuit or it is configured at a value higher than 28 A.
Short-circuit protection was tested and was working just fine.
This power supply fan runs very slowly and produces almost no noise. This power supply was running 6-7 degrees Celsius above room temperature, which is fine but a little bit higher than other good power supplies we reviewed, where they typically stayed between 2º C and 5º C above room temperature.
