Tag Apple iPhone 6s Plus

Check "About this machine" and find that there is no baseband, make up the dropped inductance and install the motherboard into the machine. Boot test shows that the version of "Modem Firmware" in "About this machine" is normal, indicating that the baseband has been working normally.

Looking at the point bitmap, it is found that this inductor is a step-down inductor supplied by S2 output from the baseband power supply. The virtual welding of the inductor leads to the lack of S2 power supply for the baseband power supply, and the baseband power supply cannot be output for the second step-down to supply power to the baseband, so the baseband does not work, and finally the mobile phone has no 4G mobile network signal.