mic1 — Missing sensor

Watchdog panic: thermalmonitord no longer receives readings from the “mic1” sensor (bottom microphone), located on the charging port flex; with no news from it for ~3 minutes, iOS restarts the iPhone, in a loop as long as the sensor stays missing.

On iPhone 12 Pro Max, iPhone 12 Pro, iPhone 12 mini, iPhone 12, iPhone 11 Pro Max, iPhone 11 Pro, iPhone 11, iPhone XS Max, iPhone XS, iPhone XR

Charging port flex (bottom microphone)

High confidenceVerified sourceMissing sensor

Watchdog panic: thermalmonitord no longer receives readings from the “mic1” sensor (bottom microphone), located on the charging port flex; with no news from it for ~3 minutes, iOS restarts the iPhone, in a loop as long as the sensor stays missing.

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.

iPhone 12 Pro Max ›iPhone 12 Pro ›iPhone 12 mini ›iPhone 12 ›iPhone 11 Pro Max ›iPhone 11 Pro ›iPhone 11 ›iPhone XS Max ›iPhone XS ›iPhone XR ›

On iPhone SE (2nd generation)

Charging port flex (bottom microphone) or broken I2C trace on the logic board

Medium confidenceVerified sourceMissing sensor

Watchdog panic: thermalmonitord no longer receives readings from the “mic1” sensor (bottom microphone); on the iPhone SE 2020, its data lines run under the SIM tray and can be cut inside the board; with no news from it for ~3 minutes, iOS restarts the iPhone, in a loop as long as the sensor stays missing.

First check

Test a known-good genuine charging port flex (iPhone 8 flexes often cause problems on the SE 2020); then diode mode on the I2C1_AP_SDA / I2C1_AP_SCL pins of the connector: OL = trace fault, to be bridged (R6610 → pin 13, R6611 → pin 15 according to Repair Wiki).

iPhone SE (2nd generation) ›

Sources