0x200000 — SMC: silent sensor
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; here, the proximity sensor on the front flex 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 Plus by disconnecting the proximity sensor (DFRWS 2025).
On iPhone 14 Plus, iPhone 14
Front sensors flex (proximity)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; here, the proximity sensor on the front flex 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 Plus by disconnecting the proximity sensor (DFRWS 2025).
First check
Inspect the front sensors flex (proximity / ambient light) and its connector, then connect a known-good flex to see if the restarts stop; diode mode on the connector if in doubt.
On iPhone 15 Plus, iPhone 15
Wireless charging coil (MagSafe, back glass)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; here, the sensor carried by the wireless coil flex 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.
First check
Check the wireless coil flex (back glass) and its connector: seating, creases, corrosion; test with a known-good back glass/coil from the same model.
On iPhone 15 Pro Max, iPhone 15 Pro
Front sensors flex (proximity)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; here, the proximity sensor on the front flex 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 15 Pro by disconnecting the proximity sensor (DFRWS 2025).
First check
Inspect the front sensors flex (proximity / ambient light) and its connector, then connect a known-good flex to see if the restarts stop; diode mode on the connector if in doubt.
On iPhone 16 Plus, iPhone 16
Wireless charging coil (back glass)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; here, the wireless coil flex sensor (a small circuit on the flex) 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. Code shown in decimal: 2097152.
First check
Check the wireless coil flex (back glass) and its connector: seating, creases, corrosion; test with a known-good back glass/coil from the same model.
On iPhone 16 Pro Max, iPhone 16 Pro
Charging port flex / barometric pressure sensor (uncertain attribution)
SMC “BSC failure” panic: the system management controller (built into the SoC) periodically waits for a response from each mandatory sensor; Repair Wiki groups this value (2097152) with 3145728 under the charging port; an iFixit thread on a 16 Pro Max with this code has no confirmed diagnosis. With no response, it forces a restart, which repeats roughly every 3 minutes (≈180 s) as long as the sensor stays silent.
First check
Work by elimination with known-good parts: charging port flex (and pressure sensor), front sensors flex, wireless coil flex.
Sources
- iFixit – iPhone SMC Panic Assertion Failed (tableau « Sensor Reference ») ↗
- Song, Yang, Lee et al. – A study on the recovery of damaged iPhone hardware exhibiting panic full phenomena, DFRWS APAC 2025 / FSI: Digital Investigation 54 (2025) 301980 – Tableau 5 (débranchement de modules) ↗
- Repair Wiki – How To Fix an iPhone 14 That Randomly Restarts (copie Wayback Machine 2026-03-02) ↗