Which update is the issue
Apple released macOS Tahoe 26.4 in March 2026, quickly followed by 26.4.1. The update brought security fixes and optimisations for Apple Intelligence. For a subset of M2 and M3 MacBooks, the update procedure halts mid-way — exactly when the base firmware (iBoot + SOC2 Secure Enclave) needs to be rewritten to the soldered NAND. Result: the device exits the update in a state that not even Apple Configurator can recover.
Symptoms — how to recognise the bug
The bug has a very specific signature. If your MacBook is in one of the situations below, it's highly likely you've been affected:
Mac won't turn on at all
After the macOS Tahoe 26.4 or 26.4.1 update, the device sits completely inert. Pressing the Power button does nothing — no boot sound, no Apple logo, no screen back-light.
USB-C charger ramps up to 20V — but boot doesn't start
A multimeter confirms the charger is correctly negotiating 20V (USB-C Power Delivery is working). Current reaches the SoC, but the processor doesn't initialise. That points to a strictly firmware issue, not power or battery.
DFU Mode can be entered, but Revive and Restore fail
Apple Configurator 2 detects the MacBook in DFU. Revive (reinstalling iBoot + recoveryOS) starts. The process halts with an error at 50–80%. Full Restore (erase + restore) fails with errors 4013, 4014 or 4031. Apple has no official solution.
Data loss on the soldered SSD
On Apple Silicon, the SSD is soldered to the logic board and encrypted by the Secure Enclave. If the firmware is corrupted, accessing the data becomes impossible through standard service methods. Time Machine or iCloud backup becomes the only way out.
Why DFU Revive and Restore fail
On Apple Silicon, the "at-home" recovery process goes exclusively through DFU Mode + Apple Configurator 2 installed on a second healthy Mac. The standard procedure:
- You connect the affected MacBook to another Mac via a quality USB-C cable;
- You force DFU entry through a specific button combination (varies on M1/M2/M3/M4);
- In Apple Configurator you choose Revive (keeps the data) or Restore (wipes everything and clean reinstalls).
With the 26.4 bug, the procedure starts normally but fails at the firmware integrity check. Errors we've seen:
| Error code | Probable cause |
|---|---|
| 4013 / 4014 | Handshake error SoC ↔ Configurator. Sign of corrupted firmware. |
| 4031 | Signature verification error — broken chain of trust. |
| 14 / 1110 | USB communication error. Appears on repeated Revive attempts. |
Confirmed affected models
- MacBook Air 13" M2 (A2681, 2022)
- MacBook Air 15" M2 (A2941, 2023)
- MacBook Air 13" M3 (A3113, 2024)
- MacBook Air 15" M3 (A3114, 2024)
- MacBook Pro 13" M2 (A2338, 2022)
- MacBook Pro 14" M2 Pro/Max (A2779, 2023)
- MacBook Pro 16" M2 Pro/Max (A2780, 2023)
- MacBook Pro 14" M3 (A2918, 2023)
- MacBook Pro 16" M3 Pro/Max (A2991, 2023)
Note: your model being in the list above does not automatically mean you'll be affected. The bug appears randomly, only on a subset of installations.
Why Apple Genius Bar can't help
The standard Apple Authorised Service Provider procedure in this case is one thing only: logic board replacement. Costs:
- MacBook Air M2 / M3: 3,000–3,500 RON + labour;
- MacBook Pro 14 M2 / M3: 3,500–4,500 RON + labour;
- MacBook Pro 16 M2 / M3: 4,500–5,500 RON + labour.
Worse: board replacement means a new SSD → complete data loss. If you don't have a recent backup, everything is lost.
Our solution — firmware-level repair
At Radical Service we approach the problem differently: we don't swap the board. We repair the corrupted firmware directly through advanced service methods that exceed Apple Configurator's capabilities:
- Full SoC diagnostic and NAND integrity check;
- Proprietary hardware intervention to rewrite the SoC2 / SEP firmware;
- Clean macOS reinstall or restore from the pre-update state (if data is critical);
- Full test: boot, charging, Wi-Fi, Bluetooth, camera, microphone, keyboard, trackpad.
✓ Duration: a few minutes of effective work.
✓ Your data stays on the SSD — nothing gets wiped.
✓ Original board preserved — no hardware replacement.
What to do if you're affected
- Don't keep trying Revive or Restore. Stop after 2–3 attempts.
- Call us at +40 739 795 800 or message us on WhatsApp — we can immediately tell whether it's the firmware bug. English spoken.
- Bring the MacBook to our office (Str. Aristotel Pappia 40, Sector 1, Bucharest) — free diagnostic, written quote before we touch anything.
- You get the repaired MacBook in a few minutes — 100% functional, with data preserved.