Below is a comprehensive guide to understanding why this happens and the best methods to resolve it. Understanding the Error: What is "Critical Init Step 3"?

For many modern MTK devices, you must short a specific "Test Point" on the motherboard to ground while plugging in the USB.

To consistently bypass "mtksu failed critical init step 3," the most effective method is If the software fails, the hardware test point remains the gold standard for forcing a successful initialization.

Most "Init Step 3" failures are caused by improper communication between the PC and the phone's VCOM port.

When managing MediaTek (MTK) devices using Software Upgrade (SU) tools or custom flashing utilities, encountering the error "mtksu failed critical init step 3" can be a frustrating roadblock. This specific error typically indicates a handshake failure between the software exploit and the device's bootloader or security chip.

If your device has a security patch newer than March 2021, the mtksu vulnerability may be patched.