Mac mini M4 Pro won't turn on or restore in DFU mode

If your Mac mini M4 Pro absolutely refuses to enter DFU mode even after following the timing pattern, the issue is almost certainly a hardware component failure or a cable limitation. [1]

Why DFU Mode Is Failing

1. The Cable is Still the Block: If you are still using the iPhone 15 Pro cable, the Mac mini will never enter DFU mode. It completely lacks the data lanes required to communicate with the host Mac. You must swap to a certified Thunderbolt 4 / USB4 cable or a USB 3.1 high-speed data cable. [1, 2]
2. Internal SSD or Power Failure: On the M4 Mac mini, if the internal modular SSD has come loose, or if there is a short on the logic board, the device will fail to hand over to DFU mode. The continuous blinking white light is the hardware's way of signaling a critical power-on self-test (POST) failure. [1]

The Final Test

To rule out user error on the button timing:

1. Unplug everything from the Mac mini (no monitors, no extra cables, no power).
2. Plug your high-speed data cable into the middle Thunderbolt port on the back of the Mac mini and the other end into the host Mac.
3. Press and hold the power button down on the bottom of the Mac mini.
4. While keeping it pressed, plug the power cable back into the Mac mini.
5. Continue holding for exactly 10 seconds. [1, 2, 3, 4]

If the front light stays white (or keeps flashing white) and never turns amber, the system cannot initialize its bootloader. [1, 2]

Next Step

Since your Mac mini M4 Pro is a recent model, it is covered under Apple's standard warranty. Do not attempt to open it. Book an appointment at an Apple Store or Apple Authorized Service Provider to have them test it with their specialized hardware tools or replace the machine entirely. [1]

If you managed to swap the cable, let me know:

• Did you switch to a verified Thunderbolt or USB 3.1 data cable?
• Is the host Mac a laptop or a desktop, and is it running the latest version of macOS?

Make sure to use the DFU port.

How to identify the DFU port on Mac - Apple Support

Did you use USB-C to USB-C cable that supports data and charging, such as the Apple USB-C Charge Cable included with some Apple products (OEM Apple cable has no icons or writing on the USB-C connectors). It works with ports on Mac that accept a type USB-C connector. Thunderbolt 3 cable is not officially supported but might work.

Make sure that nothing is plugged into any other USB port, except as needed to connect your Mac to power. If your Mac has a MagSafe port, use that port for power instead of a USB port.

Was the another Mac of any model using macOS Sonoma 14 or later [Sequoia recommended]. It might be good to set System Settings > Privacy & Security > Accessories > Allow accessories to connect: Always allow so such a prompt doesn't interrupt DFU Revive/Restore process.

Did you Restore with Apple Configurator.app or with the Finder?