Review on MCIGICM Digital Voltage Tester, Mini DC Voltmeter 2.5V-30V with 0.28 inch LED Display (Pack of 5) by Eric Avina

[UPDATE] The manufacturer seems to have fixed the issues in this review. Solder joints are much more consistent and cleaner, all modules look the same (apart from the color) and packages now have a small colored marker to indicate which module is which. Useful. You'll still need to adjust them to the desired voltage range, although this should be easy with a small Phillips screwdriver. [Old Review] > Pros: Affordable, easy to use, bright, adjustable, great addition to a DIY project. A: I got two whose ICs weren't soldered properly. I thought they were defective, but when I looked closer I noticed that there were multiple shorts. I soldered them and they worked fine. apart from being wrong. Unfortunately, they are not set at the factory, so the voltage has been switched off. Luckily, they come with an adjustment screw on the back for better calibration. I would suggest hooking up a multimeter nearby and matching the voltage on the meter to the voltage on the LCD.