Legal: Cloning or changing an IMEI to a number not originally assigned to your tablet is a serious crime in most countries (US: 18 U.S. Code § 1029). This guide is strictly for restoring your original IMEI.
Risks:
Backup First: Always use SP Flash Tool to create a Full ROM Readback before attempting any patched repair.
Why "Patched" matters here: The standard Maui META will throw a S_SECURITY_CFG_INVALID error. The patched version disables the sec_check on the TB8504X’s bootloader. lenovo tb8504x imei repair patched
Before diving into the repair, you must understand the root cause. The IMEI (International Mobile Equipment Identity) is stored in the NVRAM (Non-Volatile Random Access Memory) or the persistent partition. On MediaTek-powered devices like the TB8504X (MT8167 or MT8735 variant), this data is fragile.
Common triggers for IMEI loss include:
When standard methods fail, you receive errors like: Legal: Cloning or changing an IMEI to a
Lenovo implemented security that prevents writing to IMEI-related partitions without a special Patched Download Agent (DA).
Launch SN Writer (Run as Admin)
Load Patch File
Enter IMEI
Write Process
Reboot & Verify