After successful flash:

Follow these steps precisely. If you have a truly dead device (no vibration), you will use "Format All + Download" (last resort). For boot loops, use "Download Only."

| Symptom | Fix | |---------|-----| | No power, no PC detection | Battery replacement / EDL test point (KCOL0 short to GND) | | SP Flash Tool error STATUS_PRELOADER_INVALID | Wrong preloader; use signed preloader from correct region (CN/US/IN) | | Error S_DL_GET_DRAM_SETTING_FAIL | DDR timing mismatch; use DA (Download Agent) from MT6755_Android_scatter | | Error BROM ERROR: S_SECURITY_SF_AUTH_FAIL | Unsigned firmware; flash stock signed care firmware |