Expand Mac mini – DIY Guide

This guide outlines the steps you need to take when you receive your Expand Mac mini kit. First, physically replace the SSD module in your Mac mini. Then, perform a complete DFU restore (Device Firmware Update) using Apple Configurator to ensure your Mac mini is functioning properly with your new SSD. This guide also covers what to do if you run into boot issues during the recovery phase.

Important: This procedure will erase all data on the Mac mini. Be sure you have backups of anything you need.

Step1

Replace the SSD module from your Mac mini physically

Open your Mac mini M4 and replace the SSD module

Back up the data before proceeding

Replacing the factory SSD module

Please refer to this comprehensive guide published on iFixIt for detailed instructions and high-resolution photos for each step. There are also numerous YouTube videos demonstrating the process, such as this one by Jeff Geerling.

The necessary tools are included in the Expand Mac mini kit.

Please proceed with caution, as disassembling your Mac mini M4 involves taking it apart.

Important note: Your data on the factory SSD will be inaccessible once the new SSD is installed and the following steps are completed. Therefore, it’s crucial to back up your data before attempting this step.

Step2

Prepare the Host Mac & Firmware

Apple Configurator 2

Available free via macOS App Store

Now you need another Mac as “host Mac”

  1. Install Apple Configurator.

    On your host Mac, open the Mac App Store, download and install Apple Configurator 2.

    Confirm it’s the latest version.

  2. Download the correct IPSW file.

    From Apple (or trusted source, such as https://ipsw.me), get the full restore image (for example, UniversalMac_15.6.1_24G90_Restore.ipsw).

    Save it somewhere easily accessible (e.g. your desktop or a “Restores” folder).

  3. Launch Apple Configurator.

    Open the app; it should show its main interface (even if no device is connected yet).

Step3

Connect & Power Off the Mac mini

Connect Type-C cable to the DFU port

Avoid using Thunderbolt 3 cables

Connect & Power Off the Mac mini

  1. Connect USB-C data cable.

    Use a USB-C cable (USB 3.0 or better).

    Connect one end to your host Mac, the other to the Thunderbolt-icon USB-C port (middle port) on the Mac mini.

    Note: Avoid using Thunderbolt-only cables; they may not carry data for DFU.

  2. Make sure Mac mini is off.

    Ensure the Mac mini has no power — unplug the power cable.

Step4

Enter DFU mode on your Mac mini M4

Enter DFU mode on the Mac mini M4 to be recovered

  1. Press and hold the power button.

    Maintain the hold for 10 seconds.

  2. While still holding, reconnect power.

    With the power button still depressed, plug the power cable back into the Mac mini.

  3. Wait for the orange blinking light.

    Continue holding the power button until the status LED begins flashing orange.

  4. Release the power button.

    The display should remain black; the host Mac should recognize a DFU device in Apple Configurator.

If the status light doesn’t blink orange or the host Mac doesn’t detect anything, see Troubleshooting below.

Step5

Restore the firmware

Restore the Firmware via Apple Configurator 2

  1. Locate “DFU” device icon in Configurator.

    After successful DFU mode entry, the host shows a “DFU” icon.

  2. Drag-and-drop the IPSW file.

    Do not use Actions → Restore (which downloads a firmware file automatically — that can fail over unstable networks).

    Instead, drag your downloaded IPSW file onto the DFU icon.

  3. Confirm restore.

    Apple Configurator will prompt you to confirm. Click Restore.

  4. Wait for the restore process.

    The process may take several minutes. Do not interrupt power or disconnect cables.

  5. Automatic reboot & setup.

    After successful restore, the Mac mini will reboot and present the macOS Setup Assistant.

Watch the video demonstration above for visual guidance.

Step6

Completion & verification

Completion & Post-Restore Checks

  1. Initial macOS setup.

    Go through language, WiFi, Apple ID, etc.

  2. Verify new SSD is recognised.

    In  > About This Mac > Storage, confirm the capacity matches your new SSD.

  3. Run diagnostics / stress test.

    Optionally, use Disk Utility or third-party tools (e.g. AmorphousDiskMark) to verify performance and health.

Troubleshooting

There are some common issues that are quite likely to arise, and these can be resolved

Completion & Post-Restore Checks

Problem

Possible Cause

Suggested Fix

Apple Configurator doesn’t detect DFU device

DFU mode entry failed, cable issue, port issue

Repeat DFU entry steps; try a different USB-C data cable; use a different host Mac port

Restore fails with error codes (e.g. 4xxx, 21)

Bad IPSW file, corrupted download, SSD not seated properly

Re-download IPSW, verify file integrity; reseat SSD and tighten screws

SSD not recognised after boot

Firmware/driver issue, incorrect SSD model, connector issue

Check compatibility; ensure firmware restore succeeded; open case and verify physical connection
  • Always pre-download the ipsw files before attempting the DFU recovery, it saves a lot of time and ensures reliability.
  • If you run into Apple Configurator error codes, especially 4xxx, 2xxx, 21 or anything else, re-seating the new SSD and tighten screws will very likely to resolve the issue.
  • Changing the Type-C cable could also be helpful. After numerous of tests, we found that not all Type-C cable works. Those Thunderbolt only, especially Thunderbolt 3 cables will have problems carrying the DFU signal. Use a normal Type-C data cable is ideal.