Example (12-digit core: 49015420323751)
Digits: 4 9 0 1 5 4 2 0 3 2 3 7 5 1
Double every second from right (excluding last):
(4, 18, 0, 2, 5, 8, 2, 0, 3, 4, 3, 14, 5, 2)
Reduce >9: 4, 9, 0, 2, 5, 8, 2, 0, 3, 4, 3, 5, 5, 2
Sum = 52 → 52×9=468 → last digit = 8 ✅
Before diving into the "how", understand the legitimate scenarios:
Critical Legal Note: In most countries (US, EU, UK, India), changing an IMEI to one not originally assigned to the device is illegal. This guide assumes you are restoring the original IMEI printed on your device’s box or under the battery. Fraudulent IMEI alteration carries heavy fines or imprisonment.
Even with the correct version, problems occur. Here are fixes for frequent errors:
| Error Message | Likely Cause | Solution |
|---------------|--------------|----------|
| S_BROM_CMD_STARTCMD_FAIL | USB driver conflict | Uninstall other USB modem drivers, reinstall MTK VCOM |
| Meta failure: 0xE2 | Wrong database file | Extract fresh AP_DB and MD_DB from the exact firmware build |
| IMEI write failed – security violation | Bootloader locked | Unlock bootloader or use Bypass Utility v1.3+ with r1.5.6.1 |
| Device not found – DA error | Preloader timing issue | Try a different USB port (USB 2.0 recommended), use short test point if needed |
| Write IMEI r1.5.6.1 command not recognized | Wrong tool version | Ensure you are using a tool that explicitly supports this command syntax – some forks use different wording. | write imei r1.5.6.1
IMEI R1.5.6.1 is a solid, incremental update that keeps pace with modern chipsets. It’s not revolutionary, but the improved speed, backup safety, and broader support make it a reliable tool for professionals.
Buy if: You regularly work with recent MTK/Qualcomm Android phones.
Skip if: You only repair iPhones or older Spreadtrum-based devices.
Recommendation: Try the free version first (limited to 3 writes/day), then upgrade if needed.
I’m not sure what you mean by "imei r1.5.6.1." Possible interpretations: Example (12-digit core: 49015420323751) Digits: 4 9 0
Which of the above should I assume? If you want a full piece, I’ll assume you want a technical deep-dive about the IMEI standard and produce a structured document (specification-like) named "IMEI r1.5.6.1." If that’s correct, I’ll generate it now. If you meant something else, tell me which interpretation to use.
This guide is for educational and legitimate repair purposes only (e.g., restoring an original IMEI after firmware corruption, or understanding IMEI anatomy). Unauthorized IMEI changing is illegal in most jurisdictions.
Some older phones tie the SIM lock to the IMEI. Rewriting the IMEI with a different (but legally owned) number can unlock the device—though modern methods use server-based unlocks.
Warning: Use only to restore your original IMEI. Never use someone else's IMEI. Critical Legal Note : In most countries (US,
Run:
*#06# → compare with device label / box.
Or use imei.org/SNDeepInfo to verify TAC matches model.
| Section | Digits | Meaning | |----------|--------|-------------| | TAC | 8 | Type Allocation Code (device model & brand) | | SNR | 6 | Serial Number (unique to each unit) | | CD | 1 | Check Digit (Luhn algorithm) |
Example: 490154203237518
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