My Fairphone 3+ stopped charging properly a month ago, so I bought a new one and it was able to charge after that. Sometimes it would take a few attempts plugging in the cable to get it to recognise it was charging, but overall working fine. Then last week, as I was walking to work out of nowhere it just completely switched off and I wasn’t sure why. I opened it up and saw that a piece of the battery broke off where the pins are located, and so it seemed like that was the issue. I bought a new battery, which just arrived today but so far the phone still won’t turn on or show the charging light. I’m not sure what to do 
Most phone shops I have shown it to here in Ireland have just said to get a new phone, but I was hoping the battery alone would fix as I don’t have the money right now for a new phone. Any help greatly appreciated! Should I leave it plugged in for a while and see if anything happens? I’ve tried with multiple cables and the charging port looks clean.
There are 2 possible reasons for that behavior:
- Broken power management chip
- Sudden death (please search the forum)
What did you buy? A new FP3, a new battery, a new cable, a new USB-C port?
Even if it looks clean, it might be worth cleaning it with a toothbrush and isopropyl alcohol. I had problems like the ones you mentioned (intermittent charging, extremely slow charging, and eventually, no charging at all) and was able to fix them by cleaning the port and the contacts.
Another idea is to contact a fairphoneangel (check the angelsmap to see if there’s one in your area) to see if they can help you or try replacing a module, just in case that fixes the issue.
Good luck 