Hi! I have a Fairphone 4 that worked well for nearly 3 years. Since yesterday it is stuck into a boot loop. This was triggered by inserting the cable to charge the phone from a plane USB-C port (already reported in topic 97997).
The phone tries to boot, displays “Fairphone // powered by android” and then reboots, without even reaching the “4 blue dots” screen. By pressing main button + volume down, I can access the fastboot screen, but little else. Trying to boot in recovery mode triggers the same infinite loop. This really looks like a hardware issue. Right now I think it is probably an electric issue in the motherboard.
Things I tried that failed:
removing physical SIM card (no change)
booting without a battery: does not work (not enough power, see topic 83254)
removing the battery and letting it rest for the night (no change)
I contacted the support, but I fear there is not much to be done for this phone. I would be grateful if anyone has a clue on how to retrieve data stored in the phone.
After some additional investigation and consulting a professional phone repair provider, the most likely scenario is that my phone power management integrated circuit (PMIC) burned when I connected it to the plane USB-C port. It explains the timing and why I cannot go beyond the “Fairphone - powered by android” screen.
It is not impossible to change this chip and boot the phone (assuming the rest of the motherboard is sane). However in order to do this I would need the specification of the PMIC and ideally the motherboard schematic diagram. I could not find these specifications for the Fairphone 4 and Fairphone does not sell the motherboard as a spare part. Is there some way to get these informations?
Hi, I had the same behavior of my FP4 which was gifted to me. The installed battery was so bad, that I could not get out of the bootloop.
My solution was to get new battery. That worked for me and now the FP4 works normal.
From my understanding about rechargeble batteries I think your battery has an internal short under load situation and the voltage drops below 2,5 Volts. In this state your phone is unable to recharge the battery and can not start a correct boot.
Please also check you USB-C port. Mine was filled with dirt, so that I could not insert any cable till it locked in the port. After I carefully cleaned the port with a seewing needle, I could again see metal at bottom of the port. Maybe dirt caused charging problems also.
Update: I tried plugging in a brand new battery, my phone still does not boot. Same after letting the new battery charge on a reliable power source.
So I think some power management chip burnt and must be changed in order for the phone to restart. Recovering the data without booting the phone looks hard as the data is encrypted and requires its initial mainboard (maybe not impossible but demanding and expensive). I had a look at the technical documentation, but mainboard surgery is beyond my abilities. I am still waiting for an answer from Fairphone support.
I do not have much hope left. If anyone else reads this, backup your phone before it’s too late…
