The other day I looked at a $25 USB meter that was perfect for those who want to test if USB ports and devices such as chargers and power banks are working properly. It’s a great tool for those dabbling with gadget repairs.

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But if you’re more serious about diagnostics and repair, and have a slightly bigger budget, then you should get your hands on a full-blown USB multimeter packed with all sorts of features, from the ability to log data to identifying whether your cables support high-power charging.

This tool is the Fnirsi FNB58 USB tester. 

Fnirsi FNB58 USB tester tech

$52 at Amazon

Fnirsi FNB58 USB tester tech specs

• 2.0-inch full-color ultra-wide viewing angle TFT LCD display
• Integrated USB-A, Micro-USB, Type-C ports
• Test voltage: 4 – 28V
• Test current: 0 – 7A
• Test power: 0 – 120W
• Supports trigger detection of various fast charging protocols, QC2.0/QC3.0 trigger, FCP/SCP trigger, AFC trigger, PD2.0/3.0 trigger, VOOC/WARP trigger, Super VOOC 1.0/2.0 trigger
• E-Mark USB cable chip reader
• DASH Cable data reader

The FNB58 is an all-in-one USB tester for USB-A, microUSB, and USB-C ports. You can plug into a USB-A port directly, and to microUSB and USB-C using cables. 

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The display is a bright, crisp, clear 2.0-inch TFT LCD display, beating hands-down many other USB multimeters on the market, and making it much easier to read the information being displayed. 

With a built-in orientation sensor, the FNB58 automatically adjusts the display to accommodate the device’s orientation. The tester features an intuitive rocker switch and a back button for straightforward navigation. 

But this simplicity hides a lot of power, and I suggest downloading and getting real familiar with the user manual, because there’s a lot to this gadget and it’s easy to find yourself facing some scary-looking warnings.

One feature of the FNB58 that I really like is the real-time voltage and current waveform screen that gives me an at-a-glance idea of what the meter is sensing, which can dramatically speed up a diagnosis. For intermittent faults, the meter can log up to 9 hours of waveform data.

Another useful feature is the ability to read E-mark chip data found in higher-quality USB-C cables. This chip allows the cable to communicate with the devices it connects to, providing information about the cable’s capabilities, power capacity, and supported features.

The Fnirsi FNB58 is a powerful, versatile, and, at just over $50, affordable USB test meter. Not only does it give you the usual volts/amps power information, but can see this information as a waveform, and even do multi-hour data logging. It can read E-mark and DASH cable data, carry out cable resistance tests (this can uncover internal cable damage that is otherwise invisible), display what charge protocols are being used, and much more.

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That’s quite a list of features, and it’s far from complete.

The display is one of the best I’ve seen on a USB meter, and the user interface is simple. But there’s a lot more to this meter, and I recommend reading, re-reading, and then reading again the manual, and spending time experimenting with the meter to get used to what it can do and what to expect from it. 

If you want a cheap meter, the KJ-KayJI 2 in 1 USB tester is a good, sub-$25 option, but if you want more functionality and capability, the Fnirsi FNB58 is a huge step up for little more than double the money.

See also

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3 security gadgets I never leave home without

• 

  This replaced my multitool for a fraction of the cost

• 

  This is the perfect mini electric screwdriver

• 

  This $60 tool was a total game-changer

• 

  3 security gadgets I never leave home without