Hey there,
is there any chance to get a core modul as spare part? Mine seems dead. I already changed my broken display. I was hoping this would help. But the phone does not boot. My display led shows me the battery is charging (color is changing from blinking red over yellow to green) and my phone is vibrating when I try to turn it on. My windows computer also detects the device as Fairphone 3.
I agree with Emmanuel, there are several signs that the problem is not the core module.
I strongly recommend you check if your display is firmly connected and that there are no gaps in between display and core module. You can also disassemble and reassemble the phone as described here (especially note the comment in Step 9):
Sorry to disagree a little, Iβve had in hands two FP2s, booting, charging as indicated by the LED, from which I was able to retrieve data, but black screen. The problem was indeed the core-module which had for one visible traces of water damage and the other damaged pogo pins. So itβs quite possible the problem comes from the core-module if thorough tests have been done to prove itβs not the screen (which it seems to me here).
Not saying itβs necessarily the core-module and I can only second checking again the screens, but the signs would rather indicate me a possible core-module failure from my experience.
Did your phone have any water/moisture/bathroom experience? Quite possible it could be some water damage.