In order to use the tester you need to plug-in the (P4 / P6 or P8) connector into the tester before turning on the power supply tester by inserting the 20-pin or 24-pin ATX connector. Once the main ATX connector is installed the tester will power up and give you the readings on the power supply. Notice that the LCD display is backlit, which is a nice touch as most cases will be dark and might be under a desk. If the voltage is too low or too high an audible alarm will sound, but if it is slightly high or low it will display LL (low) or HH (high).
The first power supply I tried out was an Antec True Control 550 that I kept for legacy purposes and the fact it was the first enthusiast power supply with adjustable voltage rails on the outside of the case. This power supply is from 2003 and features a 20-pin ATX connector with a 4-pin P4 connector. After over 5 years of use it still checks out fine as you can see from the image above. The Power Good (PG) value on the lower right hand corner might be new to some people. It is the delay in time between the DC rails stabilizing and the Power Good signal being issued for the system to boot, without this signal a system will be unable to boot. A Power Good value of 250ms is considered good, but this tester reads between 100ms and 900ms. An alarm will sound if the Power Good value is abnormal.
Next up is the popular Corsair HX620W power supply, which is regarded as one of the best power supplies built in recent years. With a 24-pin ATX connector and a P8 connector in use this power supply has a little more muscle and checked out fine on the tester.
The last power supply I tried out on the tester was the Cooler Master Real Power ESA 1000W power supply, which is a beast. It looks like the Rexus power supply tester was able to handle the five year old power supplies just fine as well as the new 1000W models that are needed for the power hungry SLI and CrossFire gaming systems out there.
Final Thoughts and Conclusions:
The power supply is one of the most important parts of a computer and with the Rexus power supply tester you can not check for a defective unit in just seconds. The power supply tester is better made than those of years past and are better suited to test newer power supplies along with many of the latest connectors. The LCD display is the icing on the cake as it gives you basic voltage information right away and even the Power Good value. With this many features one would expect it to have a high price tag, but the price remains right around $20, which is what the old Antec ATX12V Power Supply Tester cost back in 2005. Obviously, you are getting more for your dollar today thanks to dropping prices in the consumer electronics market.
Legit Bottom Line: If you repair a number of computers throughout the year or live in an area with thunderstorms or power fluctuations, a power supply tester is something you need to have in the diagnostic kit!