Chosen Solution
I have an iPhone 6 that had a searching/no service issue. I reballed baseband cpu and made 2 jumpers on U1 and V1 pads and now I have a signal and everything works fine except that there is no sound on calls only. To be more precise, when someone calls me, or I call someone, I can’t hear anything in the earpiece or on loudspeaker, and headphones also doesn’t work on calls. I tested earpiece and loudspeaker in voice memo app and everything is ok, I can hear recorded sound. I also have tried with new parts (known good earpiece and charging dock flex) and it’s still the same - no sound on calls. I googled arround and found some solutions with jumpers on BB_I2S_TXD and BB_I2S_RXD lines so I have removed SIM card reader and tested this lines between BB CPU pins and test pins under SIM card reader and everuthing is ok. I also tested FPC connector readings in diode mode for eapiece pins and everything is ok to. Also tested filters and capacitors arround this connector and no problems there. I’m just out of ideas anymore on what could be wrong with the phone. Any suggestions?
At this time I know for sure that I have good PMIC on board but phone still doesn’t boot up. Any suggestions on what to check? I checked all capacitors arround PMIC and all are good (compared to my icloud locked board).
