Dynex 400 W Power Supply Review
Main Specifications
Contents
Before performing our overload tests we always like to test first if the over current protection (OCP) circuit is really active and at what level it is configured.
We configured +12V2 input from our load tester with a low current (1 A) and increased current on +12V1 input (which was connected to the power supply +12V1 rail) until the power shut down. This happened when we tried to pull more than 21 A, so OCP was active and set at 21 A. We think that is a value too far away from what is supposed to be the maximum amount of current this output can deliver.
Then we tried to pull even more power from Dynex 400 W to see what happened. Since this power supply is completely identical to Huntkey Green Star 450 W, we were expecting to explode it when we pulled around 450 W – and, yes, it happened again (third Huntkey Green Star we exploded when pulling around 450 W with the power supply hot).
So we tried several patterns before attempting to go our way to 450 W. The maximum amount of power we could pull from this unit without it exploding was 437.5 W, see the table below.
| Input | Maximum |
| +12V1 | 17 A (204 W) |
| +12V2 | 15 A (180 W) |
| +5V | 6 A (30 W) |
| +3.3 V | 6 A (19.8 W) |
| +5VSB | 2.5 A (12.5 W) |
| -12 V | 0.3 A (3.6 W) |
| Total | 437.5 W |
| % Max Load | 109.4% |
| Room Temp. | 48.6° C |
| PSU Temp. | 60.9° C |
| Load Test | Pass |
| Voltage Stability | Pass |
| Ripple and Noise | Pass |
| AC Power (1) | 616 W |
| Efficiency (1) | 71.0% |
| Final Result | Pass |
Under this load noise level at +12V1 was very high, 105 mV, but still inside ATX specs.
Short circuit protection (SCP) worked fine for both +5 V and +12 V lines.
As a tradition, below you can see the video for this power supply exploding when we pulled around 450 W from it. Keep in mind that when power supplies explode like this it means that the components from the primary were the ones not able to keep up with the amount of power being pulled by the power supply. When the problem is on the secondary (e.g., one of the outputs being overloaded), the power supply dies in silence. In other words, the over power protection (OPP) should have entered in action, what didn’t happen.