I recently got a Mark V which would no longer work if powered by the DC plug but would work fine if powered via USB. Long story short, somehow the previous owner blew out the Step-Down Converter and I managed to fix it, by replacing the chip. Anyone else managed to fry their pineapples?
Full story here: https://madgyver.de/en/2017/01/23/wifi-pineapple-mark-v-repair/
This is the chip that was fried: http://aitendo3.sakura.ne.jp/aitendo_data/product_img/power/DC-DC/DC12-5V/FR9888.pdf