Review on 5pcs Onyehn LM317 Adjustable Voltage Regulator Power Supply DC-DC ⚡️ Step-Down Converter Circuit Board - 5 Pack - Optimal for Linear Regulation by Michael Bustamante

I tested these and 2 out of 3 were bad but I need a pair for the project so luckily Revain agreed to refund me the dead boards, which are very valuable. I have 3 good ones but I can't get my time back. The heatsinks also fell off, which is normal as it makes it easier to add thermal paste. Note that this is something like a 25 pitch trimmer but it appears to be larger and I measured them around 7k ohms. I found it easier to set the trimmer to around 500-600 ohms before connecting it for testing (it provided around 5v out of 12v) as it takes a lot of turns to adjust. I've added a picture showing how I adjusted mine, clockwise the trimpot value decreased. The problem I had with the design was that they placed the input cap very close to where the screw head should have gone. The head of the M3 cap screw cleans it up easily and sits right on top of the condenser's screen-printed white outline. This shouldn't be a problem unless the capacitor or screw was installed askew, but maybe with an extra millimeter I wouldn't use that screw hole anyway. All of this to say that this isn't a bad board and if they could move the input capacitor a little further off the screw and fix the quality control issues it would be a solid 4 stars.