My rasberry pi 3b+ shows different responses to different ways i powered it it worked for the first couple of days and now is acting weird powering it via the micro usb the area near the usb gets extremely hot and the pi shows 3.4V using a multimeter (i no longer have it borrowed it off of neighbour) going through the system and i can not plug any usb devices into it otherwise it enters a boot loop. powering it via the gpio 5v and Ground the ones that are next to each other the pi will not turn on indicating gpio pin failure and but if i put the ground to the other at the bottom it boots with red power led but no activity led unlike when it was powered via the micro usb. the area near the usb still gets hot i thought it was the polyfuse and left it for a few days still got the same result and now the 5v pins at the top of the gpio pin layout no longer give any response when i use the multimeter. i would like some assistence i don’t have any pictures as of yet but if you want some i will upload them but i will not be able to show any multimeter measurements i will also reply late as i have work all day and no mobile internet (i hate prepaid).
the gpio power setup is a 12v (used to power a fan active cooling) psu brick that has been stepped down to 5v (for the pi) through a dc to dc buck converter and has been preconfigured to run 5.1v before i plugged it into the pi it worked with another one i had before this but that showed no activity regardless of what method i used to plug it in or what os i was running and that turned out to be a factory defect this is a new pi i got from that warrenty. power spikes also i don’t think was the issue as the voltage stays even when a multi meter is put on it.
look fowared to hearing what you have to say