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CoodMax/MG MG-P500W
CoodMax? What kind of a name is that? Maybe it’s supposed to be a knock-off of the USA-based CoolMax, which is already not known for quality products. Interestingly, the newer power supplies from them are branded “MG”, like the one we have here, but CoodMax is still the company behind them. This is a brand I’m not very familiar with, so I really have no idea how this is going to end.
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Huh? We have 26.4W on the 3.3V Rail, 45W on the 5V Rail, 144W on the 12V rail, 6W on the −12V Rail, and 7.5W on the 5vsb rail. Apparently, that makes 500W. Maybe the model name stands for Maths Grade – Poor 500W. It’s actually 228.9W. Let’s see if the maths on the label is the only thing wrong with this product.
Load Testing
Test 1 (116.67W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 4.85A | 12.13V | 40.2mV |
| 5V | 4.93A | 4.93V | 13.2mV |
| 3.3V | 10.09A | 3.33V | 36.2mV |
| −12V | 0A | −12.23V | 18.6mV |
| 5Vsb | 0A | 5.04V | 24.4mV |
| AC Power | 146.67W | ||
| Efficiency | 79.61% | ||
| Power Factor | 0.6 | ||
Test 2 (206.32W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 9.75A | 12.19V | 66.8mV |
| 5V | 9.76A | 4.88V | 24.8mV |
| 3.3V | 10.09A | 3.33V | 39.2mV |
| −12V | 0.1A | −12.44V | 50.8mV |
| 5Vsb | 0.99A | 4.96V | 30.8mV |
| AC Power | 249.78W | ||
| Efficiency | 82.60% | ||
| Power Factor | 0.57 | ||
Test 3 (262.13W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 14.46A | 12.05V | 80.4mV |
| 5V | 9.8A | 4.9V | 31.6mV |
| 3.3V | 10.09A | 3.33V | 40.8mV |
| −12V | 0.11A | −12.77V | 66.0mV |
| 5Vsb | 0.99A | 4.09V | 33.4mV |
| AC Power | 316.73W | ||
| Efficiency | 82.76% | ||
| Power Factor | 0.58 | ||
Test 4 (315.69W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 19.06A | 11.92V | ? |
| 5V | 9.88A | 4.94V | ? |
| 3.3V | 10.09A | 3.33V | ? |
| −12V | 0.11A | −13.17V | ? |
| 5Vsb | 0.99A | 4.94V | ? |
| AC Power | 399.64W | ||
| Efficiency | 78.99% | ||
| Power Factor | 0.58 | ||
This is really only a 260W power supply. During Test 4, it ran long enough to read the voltages and AC power draw, but it failed after that. Before it died, though, the performance was unremarkable. The voltages and ripple didn’t get outside allowable limits at any time during the testing, but there’s still plenty of room for improvement. The efficiency stayed around the 82% mark for the most part. Again, this is unremarkable. It could be better, but could be worse.
| Rail | Test 2 (206.32W) | Test 3 (262.13W) |
| 12V |  |
 |
| 5V |  |
 |
| 3.3V |  |
 |
| −12V |  |
 |
| 5Vsb |  |
 |
A Look Inside
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It’s not quite as gutless as the Aywun, but it’s still no where near as good as some others in this roundup, such as the Thermal Master. The input filtering consists of an X capacitor, a common-mode choke, and three ceramic capacitors (including one after the rectifier). It’s better than nothing, but there should be an extra choke, and an extra X cap. It has four individual diodes instead of a bridge rectifier, rated at 2A. The two primary capacitors are 470µF parts branded Sun. The switching transistors are MJE13007s. I couldn’t identify the real manufacturer, but in all likelihood, they are similar if not identical to the original Motorola MJE13007s, which are currently produced by ON Semiconductors.
The secondary rectifiers look to be from the same manufacturer as the switching transistors. The 5V and 3.3V rails use MBR1645CT rectifiers. Micro Commercial Components is the only manufacturer with a similar part number (although their logo looks nothing like the one on the rectifiers). I’ll wager the parts used in this power supply have similar specifications to the MCC ones, so they are probably rated for 16A. The 12V rail uses an FD16F20CT Rectifier. I couldn’t find a datasheet from an alternative manufacturer, but the part number suggests it’s a 16A fast recovery rectifier. The capacitors on the secondary side are all branded Asia’X, which are basically re-sleeved Fuhjyyu parts. Fuhjyyu have an appalling reputation for reliability, so it’s unlikely that these capacitors will last very long.
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The fan is branded Ever Cool. It runs at a fixed speed, since the power supply lacks a fan controller. It was audible, but only just. Like the Aywun A1-1000, the heat sinks are insanely thin, and I can easily bend them with my bare hands.
Specifications and Conclusions
| Real Wattage | 260W |
| OEM | Topower |
| PFC | None |
| Price | $20 AUD |
| ATX Connector type | 20+4 pin |
| Worst-case voltage regulation (12v, 5v, 3.3v) | 2.8%, 1.4%, 0.6% |
| Worst-case ripple (12v, 5v, 3.3v) | 59.2mV, 28.6mV, 8.6mV |
| Worst-case efficiency | 78.99% |
| Input filtering | Indequate |
| CPU Connector | ATX12v (4 pin) |
| PCI-E Connectors | None |
| Molex (Peripheral) Connectors | 3 |
| FDD Power connectors | 1 |
| SATA Power connectors | 4 |
Pros: Reasonable voltage regulation, Reasonable Ripple suppression, Quiet
Cons: Can’t deliver 500W, Very low quality capacitors, Inadequate input filtering, Very thin heat sinks
Score: 3/10
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