Best [patched] — Brom Disabled By Efuse 0x146
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.
a. Identify the exact SoC and board
Look for markings on the main chip (e.g., RK3566, RK3588, Allwinner, Amlogic). Different vendors use different error codes. brom disabled by efuse 0x146 best
b. Check hardware-level recovery options
- Short test points (D+/D- or recovery pin): Some Rockchip devices can force USB boot by shorting specific pins (e.g., eMMC clock or data pin to ground) during power-on.
- Boot from alternative media (if not fused out): Try SD card with a known working bootloader (e.g., U-Boot or Rockchip MiniLoader).
3. Best for End-Users (No Dongle): Shorten CLK/Pin Method
This is a hardware trick used when the device is completely dead (no preloader). It involves shorting two test points on the motherboard (CLK and GND) right when the BROM starts.
- Why it works: The clock glitch confuses the BROM’s authentication timing, allowing it to accept an unauthorized DA once before the full check completes.
- Risks: High risk of shorting the wrong pins and frying the CPU.
- Best done with: A pre-made "MTK BROM Bypass" dongle or an Arduino with a precise delay script.
- Success rate: 40% (depends on board revision).
What is an Efuse?
An Efuse (Electronic fuse) is a one-time programmable (OTP) memory cell inside the SoC. Once a bit is "burned" from 0 to 1, it can never be changed back. Manufacturers use efuses to: It sounds like you’re encountering a low-level boot
- Disable debug interfaces permanently.
- Enable Secure Boot irrevocably.
- Lock the BROM to prevent unauthorized flashing.
Final Verdict
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. Short test points (D+/D- or recovery pin) :
Option C: Replace the Motherboard / CPU
- The cheapest practical solution for a common phone.
- Find a motherboard from a phone that never received the eFuse-blowing update.
7. Real-World Example
Device: Redmi 9C (MediaTek Helio G35)
User action: Tried to flash a patched boot image via SP Flash Tool after a 2021 OTA update.
Result: BROM: Disabled by eFuse 0x146
Outcome: Phone dead. No free fix. Motherboard replacement cost: $40. JTAG repair cost: $80.
2. Possible Causes
- Secure boot fused: Manufacturer burned eFuses to disable loading unsigned code.
- Boot source limited: eFuse programmed to boot only from a specific device (e.g., eMMC) and that device is empty/corrupt.
- Recovery mode disabled: Some chips let OEMs blow fuses to disable Mask ROM (BROM) recovery modes permanently.
- Hardware damage or power glitch: Rare, but corruption or incorrect voltage during eFuse programming can trigger false errors.