Camera Still Dont Work After Replacement

I thought replacing camera both front and rear solves the camera shutter hang/black screen.

but still the camera wont work, flashlight dont work as well.

i tried pressing the camera reverse to check what camera is broken, it keeps the camera app freeze, and i have to kill them from background.

i tried restoring, but it doesnt help.

am i looking at its main board now? but the problem is, i dont know where to begin to diagnose.

can anyone show me a picture on how to solve this? i checked the board, no chip has been removed nor damaged, but i dont know if they are still functional, and besides i dont know where is the chip that is related to the camera.

please help.

thank you,