The manufacturer has blown the eFuse to enable Secure Boot.
If the efuse at 0x146 is truly burned, and no authenticated DA exists, no software trick will help. This is because the decision is made in hardware within microseconds of power-on.
If you see "brom disabled by efuse 0x146", consider the device for parts or professional motherboard replacement. There is no software button or free tool to fix it.
For technicians: Only an authorized EMI authentication file or direct eMMC programming (JTAG/ISP) can bypass this — and that requires factory-level credentials or hardware intervention.
"BROM disabled by efuse 0x146" is a security measure implemented by manufacturers (most notably on
devices like Vivo, Samsung, and Oppo) to block unauthorized access to the BootROM (BROM) mode. This prevents common "one-click" bypass tools from exploiting the device for FRP (Factory Reset Protection) removal, unlocking, or flashing. Understanding Efuse 0x146 Physical Lockdown
: The "efuse" is a microscopic fuse within the CPU. Once "blown" (set to a specific value like 0x146), it permanently disables certain hardware pathways, such as the emergency BROM port. Security Evolution
: This update was released to counter the widespread use of Python-based BROM exploits. Devices with this efuse set will no longer enter BROM mode via standard "Volume Up + Down" button combinations. Software vs. Hardware
: While some older security patches disabled BROM via software (which could be bypassed by shorting a CLK pin to ground), the
status often indicates a hardware-level lock that makes traditional "Test Point" methods much more difficult or impossible on certain models. Best Solutions for 0x146
Since standard BROM exploits are blocked, you must use methods that target the mode instead of the BootROM: Preloader Auth Bypass : High-end servicing tools like the Unlock Tool UMT (Ultimate Multi Tool)
have updated their protocols to communicate through the Preloader port rather than forcing BROM. Custom DA/Preloader Files
: For many Vivo and Samsung MTK devices, you must select the specific model in your tool and use a "Custom Preloader" or "Custom DA" (Download Agent) file that is compatible with the new 2023+ security patches. VBOOT/Meta Mode : Some operations can still be performed in Factory Mode , which do not require the BROM exploit to function. Hardware Test Points brom disabled by efuse 0x146 best
: If software-only methods fail, you may still need to find a physical Test Point
on the motherboard to force the device into a state where the Preloader can be overwritten, though this is increasingly rare for 0x146-level security. Recommended Tools Unlock Tool
: Widely considered the most frequent updater for bypassing "New Security" on MediaTek. Pandora Box
: Known for stable Preloader-based communication for Samsung and Vivo devices. DFT Pro / Hydra Tool
: Alternative professional suites that support "Force Brom Fail" solutions. Are you working on a specific model
(e.g., Vivo Y21, Samsung A03s) so I can provide the exact test point or tool configuration?
Here’s a clean, informative text based on your request:
System Alert: BROM Disabled via eFuse 0x146
The Boot ROM (BROM) has been permanently disabled due to the programming of eFuse address 0x146. This action is typically irreversible and prevents any further execution of the boot ROM code on this device.
Possible causes:
Implications:
Recommended action: Verify that the main bootloader is intact. If boot failures occur, the device may require JTAG or hardware-level recovery, depending on the platform. The manufacturer has blown the eFuse to enable Secure Boot
Understanding "BROM Disabled by efuse 0x146": Causes and Fixes
If you are trying to flash a MediaTek (MTK) device and encounter the error "BROM disabled by efuse 0x146", you’ve hit one of the most frustrating security roadblocks in modern smartphone repair.
This error typically appears in SP Flash Tool or custom unlocking software when the device’s Boot ROM (BROM) has been hardware-locked by the manufacturer. What Does "efuse 0x146" Actually Mean?
MediaTek processors have a low-level boot mode called BROM (Boot ROM). This mode is essential for unbricking phones because it communicates with a PC before the Android OS or even the Bootloader starts.
The efuse 0x146 is a physical hardware fuse inside the CPU. When a manufacturer (like Xiaomi, Vivo, or Oppo) "blows" this fuse during production, it tells the chip: "Do not allow unauthorized access to BROM mode via the standard USB cable shortcut."
When you see this error, it means the software is trying to send a command to the BROM, but the CPU is rejecting it because the security fuse is active. The Best Ways to Fix "BROM Disabled by efuse 0x146"
While you cannot "un-blow" a physical hardware fuse, you can bypass the restriction using these industry-standard methods. 1. Use the "Test Point" Method (Hardware Bypass)
Since the software shortcut to BROM is disabled, you must manually trigger it.
How it works: You open the back of the device and use a pair of tweezers to short a specific gold point (the Test Point) on the motherboard to the Ground (GND).
Why it works: Shorting the Test Point forces the processor into BROM mode, bypassing the efuse check that happens during a standard button-combination boot.
Best Practice: Search for your specific model's "Test Point diagram" online before attempting. 2. Use MTK Auth Bypass Tools
Many modern MTK devices require an "Authentication" file to flash. If you are getting the 0x146 error, it often means the tool is failing the handshake. If you see "brom disabled by efuse 0x146",
Solution: Use a tool like MTK Auth Bypass Tool (by MCT) or LibUSB. These tools "exploit" the stack to disable the security check momentarily, allowing SP Flash Tool to communicate with the device. 3. Update Your DA (Download Agent) File
Sometimes the error isn't just the fuse; it's that the software doesn't know how to talk to your specific chip version.
The Fix: Ensure you are using the correct Custom DA file for your specific model (e.g., MT6765, MT6833) rather than the default MTK_AllInOne_DA.bin. 4. Switch to Preloader Mode
If BROM is permanently disabled and Test Points aren't an option, some tools allow you to flash via Preloader Mode.
Instead of holding buttons to trigger BROM, you simply plug the phone in while it is powered off.
Note: This requires a "signed" firmware package that matches your device’s region and version exactly. Critical Warnings
Avoid "Force BROM" Scripts: Some scripts claim to force BROM via software on 0x146 devices. Use these with caution, as they can lead to a hard brick if the preloader is corrupted.
Check Drivers: Ensure you have the MediaTek USB VCOM drivers installed correctly. A "Device Not Recognized" error can sometimes mimic an efuse error.
The 0x146 efuse is a hardware-level security lock. The best and most reliable solution is almost always the Test Point method. It physically overrides the security check, giving you full access to the chip for flashing, unlocking, or repair.
Do you have the Test Point diagram for your specific device model, or should we look for that next?
The "BROM disabled by efuse 0x146" error indicates that newer MediaTek devices have had their Boot ROM mode permanently hardware-locked, preventing standard flashing methods. Resolving this requires using specialized service tools (e.g., UnlockTool, CM2) in Preloader mode, applying MTK auth bypass scripts, or finding hardware test points to force communication. For more details, visit xda-developers.com
It sounds like you’re encountering a low-level boot failure on an embedded system (likely a Rockchip or similar ARM-based SoC), where the mask ROM (BROM) is being disabled due to an eFuse configuration. The code 0x146 typically points to a security or fuse-related policy that prevents further booting.
Here’s a guide to understanding and troubleshooting this issue.
This error is most commonly encountered when attempting to flash firmware (using tools like SP Flash Tool or Miracle Box) on MediaTek (MTK) Android devices.
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