Have a 4.3 heatermeter and a pi3b+ about a year old about a month ago it started dropping wifi connection now it won't connect at all. Reloaded software and tried new sd card. Reset config will not work and only the red light on the pi lights. I have about 6.5 volts feeding the pi on pin 2&4 on the pi pinout, and 0 volts on pins 1 & 17 which is the 3v3 pins. So i'm suspecting the pi has met it's fate. What would a good replacement be i need wifi . second question is why would the heatermeter be supplying 6.5 volts to the Pi is this what did the pi in? Also i know very little about computers.