[Solved] How to fix Restore Error {err} in Finder / iTunes caused by NAND communication timeout during early bootloader initialization on iPhone 14 Pro

[Adam Medina]

Diagnostic Hardware Specs: iPhone 14 Pro | OS Version: iOS 17.6 | Archive Source: Apple Support Community #256572003

I am running into a persistent issue on my iPhone 14 Pro running iOS 17.6.
Whenever the machine encounters NAND communication timeout during early bootloader initialization, the following diagnostic log appears in Console:

AOSKit: [Restore] Device state transition failed: result code 9 during secure boot image verification

I verified that hardware connections are intact and tested across different power sources. What is the verified diagnostic procedure to permanently eliminate this symptom?

Mac Studio M2 Max (32GB) | EIZO ColorEdge CG279X | Wacom Intuos Pro | Antwerp, BE

Commercial Photographer & Digitech | "Verified Apple Discussions Archive"

[Victoria Harrison]

Apple Recommended / Verified Community Solution

This canonical solution was verified and marked as solved in the Apple Support Community archive.

Direct Thunderbolt connection, forcing true DFU mode, and executing an in-place software update or Configurator revive.

Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

1. Never select ‘Restore’ if data is unbacked-up; always select Update.
2. Use an authentic Apple USB-C 60W/240W cable connected directly to Mac ports (no hubs).
3. Enter true black-screen DFU mode and execute an Apple Configurator Revive Device pass.

Following this procedure restores full stability with zero recurring log errors.

MacBook Pro 14″ M2 Max (32GB) | Pro Display XDR | iPad Pro 13″ M4 | Lyon, FR

Apple Certified Support Professional (ACSP) | Product Designer & Design Systems Lead

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