Review on 💥 Comidox 1PCS DC-DC High Voltage Boost Converter: ZVS Step-up Booster Module for Capacitor Charging – Adjustable Voltage Output, 8~32V to 45~390V Power Supply by Tyrone Lee

As others have said, I also had an issue with one of the screws on the input connector. One of the bolts was stuck and wouldn't turn all the way in. I literally had to unsolder the entire screw terminal and replace it with my own. While at it I fixed a whole bunch of unfinished solder joints that looked like they were done by a complete amateur. I also noticed that all other modules like this one have three 10uF 400V caps (green) on the top of the board. . I have two of these but there is room to solder a third. There is no US3M SMD Ultra Fast Rectifier on the underside of the board, but again there is a spot for soldering. It even has a silkscreen on it indicating there should be an SMD diode. This diode is present on other models. Even the picture of this product shows three of these rectifier diodes, but I only have two. Finally, a small rectangular nickel strip jumper is soldered on here, while other boards have a real SMD fuse there. Maybe they removed those components to get the maximum gain and sacrifice soldering? Who knows. I'm not sure how differently this board would perform if it didn't have a capacitor and rectifier diode. This board also makes a high pitched squeak when I put weight on it. One of the two 10uF caps has already started to bulge slightly at the vent. I'm here, it's only a matter of time before this thing explodes on me. Get a different model.