I received a dodgy batch of DC-DC converters. These are pretty common 12-19V in and 3.3V out. The top one is a dodgy one from the supplier. The bottom one is working unit from another supplier. You can see that the resistor and capacitor (between inductor and chip and between chip and bottom left solder pad) are transposed. They probably just loaded the wrong reels. I can fix these but it's a pain in the butt. The seller ended up giving me a partial refund. The middle is where I've desoldered the R and C and swapped them to their correct positions. The issue, however, is that the R is incorrect also resulting in 3.6V... I'll need to buy some parts and fix them.