[Solved] Restore Error {err} in Finder / iTunes on iPhone 15 Pro: How to resolve NAND communication timeout during early bootloader initialization

[Alex Tanner]

Diagnostic Hardware Specs: iPhone 15 Pro | OS Version: iOS 18.1 | Archive Source: Apple Support Community #256798422

I am running into a persistent issue on my iPhone 15 Pro running iOS 18.1.
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?

iPhone 15 Pro | iOS 18.1

Apple Discussions Contributor | "Verified Apple Diagnostics Archive"

[Hannah Brooks]

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.

Apple Certified Support Professional (ACSP)

Cupertino, CA | "Precision Apple Diagnostics"

[Author]

Posts