Review on 🔌 6-Pack Valefod LM2596 High Efficiency Buck Converter DIY Power Supply Step-Down Module - DC to DC Voltage Regulator 3.0-40V to 1.5-35V by Johnnie Trimble

I saw several other reviews saying this product is good or not good and decided to take a chance as I really only needed one of them. I bought them to step down the voltage from the 3D printer's power supply to 5 volts to power the Raspberry Pi 4. I soldered everything together, took out the multimeter and started turning the screw to reduce the output voltage. I turned this screw many times and the output voltage stayed the same. I did a google search and people said you probably have to turn the screw a lot so I kept turning and turning and turning to no avail. After 30 minutes of twisting and swearing, I decided to replace the converter with another one. This worked perfectly and got the tension I needed in a few turns of the screw. I have no idea if the others are good or not, but if I never need one again, hopefully one of the remaining 4 will work.