0x40000 — SMC: silent sensor
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; the iFixit table associates this value with the battery. With no response, it forces a restart, which repeats roughly every 3 minutes (≈180 s) as long as the sensor stays silent.
Sources disagree on this code. Both readings are shown: confirm with a known-good part.
On iPhone 13 Pro Max, iPhone 13 Pro, iPhone 13 mini, iPhone 13
Battery (value from the iFixit table, probably wrong)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; the iFixit table associates this value with the battery. With no response, it forces a restart, which repeats roughly every 3 minutes (≈180 s) as long as the sensor stays silent.
First check
Check whether the battery percentage is displayed (a reading stuck at 0–1% reveals lost battery data), inspect the battery connector (bent pins), test with a known-good battery, then measure the connector's data lines in diode mode.
iPhone 13 Pro Max ›iPhone 13 Pro ›iPhone 13 mini ›iPhone 13 ›
On iPhone 14 Pro Max, iPhone 14 Pro
Charging port flex (Lightning)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; here, the charging port flex sensor has stopped responding. With no response, it forces a restart, which repeats roughly every 3 minutes (≈180 s) as long as the sensor stays silent. Reproduced on iPhone 14 Pro by disconnecting the USB module (DFRWS 2025).
First check
Check the seating and condition of the charging port flex (tears, corrosion, FPC connector pins), then test with a known-good genuine flex; if the panic persists, measure the connector pins on the logic board in diode mode.