If you are searching for the keyword , you are likely facing the dreaded "Invalid IMEI" or "Null IMEI" error on a Chinese tablet or smartphone. Fortunately, the Ultimate Multi Tool (UMT) remains one of the most reliable solutions for this exact problem.

This article is a deep dive into everything you need to know: why IMEIs vanish, how the UMT tool fixes them, step-by-step guides, driver installation, and troubleshooting common errors. Before we fix the issue, we need to understand why SPD (Spreadtrum) chipsets are notorious for IMEI loss. Unlike Qualcomm or MediaTek devices, SPD phones store critical NVRAM data (including IMEI, Bluetooth address, and Wi-Fi MAC) in a partition called ProdNV or Calibration File .

| Tool | Cost | Effectiveness on SPD | Ease of Use | | :--- | :--- | :--- | :--- | | | Free | Low (fails on Android 10+) | Very Hard (requires BROM mode + md DB) | | SPD Upgrade Tool (ResearchDownload) | Free | None (cannot write IMEI, only flash) | Medium | | Hydra Tool | Paid | Good, but slower NVRAM scanning | Medium | | Octopus Box | Paid | Excellent for SC9832/7731, weak on Tiger | Medium | | UMT | Paid (One-time) | Excellent (supports Tiger/Shark fully) | Easy (Automated) |

In the world of mobile phone repairing, two things often strike fear into the heart of a technician: a dead boot and a null IMEI. For Spreadtrum (now Unisoc) based devices, losing the IMEI number is a common firmware glitch that turns a smartphone into a useless media player.