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[Solved] How to fix MagSafe 3 Blinking Amber LED and Refusing to Charge caused by SMC Power Delivery controller handshake fault on MacBook Pro 16″ M1 Pro

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Home › Forums › Battery, Charging & Thermal Care › [Solved] How to fix MagSafe 3 Blinking Amber LED and Refusing to Charge caused by SMC Power Delivery controller handshake fault on MacBook Pro 16″ M1 Pro

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  • November 14, 2026 at 4:51 pm #8374
    Nina Patel
    Apple Master (Lvl 10)
    Diagnostic Hardware Specs: MacBook Pro 16″ M1 Pro | OS Version: macOS Sonoma 14.6 | Archive Source: Apple Support Community #256516862

    I am running into a persistent issue on my MacBook Pro 16″ M1 Pro running macOS Sonoma 14.6.
    Whenever the machine encounters SMC Power Delivery controller handshake fault, the following diagnostic log appears in Console:

    AppleSmartBattery: [Power] MagSafe 3 EPR 28V/5A handshake negotiation rejected: resistance anomaly

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

    MacBook Pro 16″ M1 Pro | macOS Sonoma 14.6
    Apple Discussions Contributor | "Verified Apple Diagnostics Archive"
    November 14, 2026 at 4:51 pm #8375
    Hannah Brooks
    Apple Master (Lvl 10)
    Apple Recommended / Verified Community Solution
    This canonical solution was verified and marked as solved in the Apple Support Community archive.

    Completely discharging GaN brick capacitors, cleaning pogo pins with 99% IPA, and triggering PMU cold reset.

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

    1. Unplug power brick from the wall and disconnect MagSafe cable. Wait 2 full minutes for capacitors to discharge.
    2. Clean the 5 gold spring-loaded pins with 99% isopropyl alcohol and a lint-free swab.
    3. Plug adapter directly to wall, connect MagSafe to Mac, and power on. The LED will illuminate steady amber.

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

    Apple Certified Support Professional (ACSP)
    Cupertino, CA | "Precision Apple Diagnostics"
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