オリジナル投稿者： Minho ,
Looks like you did an exhaustive troubleshooting…for someone who says they don’t understand all the interactions, you have done a thorough job! I don’t have a solution per se but I’ll make a few suggestions which may help you find the problem. Some of these you may have already tried but not documented: * The first thing I would do at this point is validate the condition of my parts. Can you try the Taptic engines in a working phone? You have to know 100% that the original and the replacement do indeed work. * Is U3800 getting power? Obviously VCC_MAIN works but have you looked at the power on pin 2 of the L3800 coil and PP_ARC_VBOOST? You should be measuring 8V there. I don’t know if the 8V is always there or not which leads me to the next point… * Check the AP_TO_ARC_RESET_L line to see if it is Low (0V). That would keep the Arc driver in RESET mode and disable it. Similarly, look at the I2C lines (I2C1_AP_SDA/I2C1_AP_SCL). Check them in diode mode (they should be balanced) and then power the device and measure the voltage (it should read 1.8V). * On the right side of the schematic, check the current sense lines for continuity (SOLENOID_TO_ARC_DRIVER_VSENSE_P). There are Resistors and Filters downstream that may have been dislodged or damaged. Good luck, be sure to report back!