Useful isolation, not “100% OK”
Standalone progress can reduce suspicion on some top-board functions, but it does not certify every CPU/NAND/RAM connection or guarantee all normal-board conditions.
IPHONE BOOT / RESTART / PANIC FORENSICSFollow the boot.
Follow the boot.
Parse the panic.
Correlate current shape, Apple-logo behavior, NAND access, kernel/sensor initialization, watchdog timing, USB/restore state and panic evidence before board rework.
8-STAGE BOOT / WATCHDOG HIGHWAY
POWER
LOGO
NAND
KERNEL
SENSORS
WDT
UI
BASEBAND
Trace all eight stages. Current, screen state, USB/restore state, panic evidence and measured checkpoints must agree before a hardware conclusion.
01 — IOS BOOT SEQUENCE
Trace all eight boot stages
V3 uses the uploaded eight-stage pipeline and converts each stage into symptom → expected evidence → confirmation test → next action.
02 — CURRENT / RESTART SIGNATURE PROFILER
Read the curve together with boot state
The uploaded current examples remain available, but no current signature is treated as a single-component diagnosis.
SELECTED BOOT BEHAVIOR
03 — PANIC-FULL FORENSICS ENGINE
Extract the token, then map the subsystem
V2 parses sensor tokens and hardware keywords but does not jump directly from token to replacement.
04 — SENSOR / HARDWARE CODE LOOKUP
Hex + decimal + binary + subsystem description
The two uploaded screenshots are incorporated as a technician lookup table. These labels are source-derived; model-specific interpretation still needs confirmation.
| Hex | Decimal | Binary | Source Description | Diagnostic Branch |
|---|
05 — FAILURE DOMAIN ISOLATION MATRIX
NAND vs sensor vs baseband vs power
Use multiple independent observations. No row is a one-to-one diagnosis.
| Domain | Current / behavior clue | Timing | Screen / USB clue | Useful confirmation | Do not assume |
|---|---|---|---|---|---|
| NAND / NVMe | Early drop, DFU-like state, restore/read-write failure | Early boot / restore | Logo may flash off; DFU/Recovery possible | Storage rails, reset, interface, exact restore log, read/write evidence | 0.075A or Error 4013 alone proves NAND |
| Sensor / I²C / I3C | Late logo loop or watchdog pattern | Driver init or ~180s watchdog | Panic may name missing sensor or bus | Exact panic token, bus state, flex isolation, known-good part | Every rebound loop is front-flex failure |
| Baseband / Interposer | Late hang, modem missing, radio/userspace fault | Late boot / modem init | May boot with no baseband or hang depending fault | Baseband power/reset/clock/IPC, modem identity, board-layer isolation | 20% restore or dim logo proves interposer |
| Power / Battery / BMS | Drop/reset under load, battery telemetry faults | Load dependent / random | Camera/GPU load may trigger reset | VBAT droop, battery current, BMS telemetry, known-good battery/PSU test | Load restart automatically means bad BMS |
| Display / Touch / UI | Boot continues but screen/touch abnormal | SpringBoard / UI | Sound/vibration/USB may prove OS is alive | Display/touch rails, known-good panel, MIPI/reset, connector inspection | Black screen means no boot |
06 — BOOT SIGNAL / VOLTAGE / GR DATABASE
Measure the line before naming the subsystem
Uploaded-source values are preserved as page references, not universal factory specifications.
| Subsystem | Signal / Rail | Voltage | GR / Diode | Resistance | Scope / State | What abnormal supports |
|---|
07 — LIVE BOOT-LINE EVALUATOR
Combine GR, voltage and boot stage
Use this to classify the electrical state of a line. It deliberately does not name a failed IC from one reading.
08 — INTERPOSER / RESTORE GUARDRAILS
Isolation evidence is not absolute proof
The strongest V1 rules are rewritten as conditional evidence.
Restore percentage is not a universal map
Use exact Finder/iTunes/Apple Devices logs, USB stability, restore stage, NAND rails and baseband/sensor evidence instead of percentage alone.
Error code is stage evidence
Do not automatically remove/reprogram NAND. Rule out USB transport, sensor/bus faults, storage power and restore-image issues first.
Disconnect test is useful, not a 90% rule
After screen/liquid work, front-sensor isolation is reasonable when panic/bus evidence supports it, but the exact cause should still be measured.