A jagged sinewave on your FNIRSI multimeter’s function generator means the signal is not clean. This can mess up your tests on audio circuits or sensors, so fixing it is important for accurate readings. The jagged look often comes from a poor ground connection or a noisy power source. I have found that simply switching … Read more

If you own an FNIRSI multimeter, you know its screen can be frustratingly small. Reading those tiny numbers is a common problem that can make your work slow and annoying. I have found that the bright blue backlight actually makes things harder in direct sunlight. Tilting the meter slightly or cupping your hand over the … Read more

You press the trigger mode button on your FNIRSI multimeter and the waveform on the screen vanishes. This is a common point of confusion, and Why it happens is key to getting accurate readings. The trigger mode is not broken; it is simply waiting for a specific electrical event. Your waveform disappears because the signal … Read more

You plug in your FNIRSI multimeter and notice the battery icon lights up even while you are testing circuits. This is confusing because you expect it to only charge when turned off. In my experience, many modern multimeters allow pass-through charging. This means the device can run directly from the USB power while simultaneously topping … Read more

You unboxed your new FNIRSI multimeter, excited to test it, only to find the plug connection is loose or broken. This frustrating defect can stop you from using your tool right away, which is why The cause matters so much. In my experience, a defective plug connection often happens from rough handling during shipping, not … Read more

Updating the firmware on your FNIRSI multimeter can fix bugs and add new features. But when the official setup instructions fail, you need a different approach to get your device working correctly. I have found that most setup failures happen because of a missing driver or wrong boot mode. The computer simply does not recognize … Read more

Figuring out how to measure cable resistance with your FNIRSI multimeter can feel tricky when the manual is bare bones. Getting this right matters because bad cables cause power loss and device failures. Many people think any low reading means a good cable, but even a tiny 0.5 ohm increase can overheat a charger or … Read more

You just bought a new FNIRSI multimeter with a temperature setting, but no thermocouple came in the box. This is confusing because you expected to measure heat right away. Most multimeters are sold as basic tools, and the thermocouple is a separate accessory you buy based on your specific needs. FNIRSI keeps the price lower … Read more

You open your toolbox to grab your older FNIRSI multimeter, and the screen is dead. You just replaced that 9V battery last week. This frustrating problem happens when the meter drains power even while switched off, costing you time and money. The issue is often a hidden internal current leak, not a faulty switch. Many … Read more

You want to know how to make your FNIRSI multimeter see logic-level MOSFETs properly. This matters because these parts need very little voltage to turn on, and a standard test might miss them. The trick is that your multimeter’s diode mode may not supply enough voltage to fully trigger a logic-level MOSFET. You might need … Read more