Skip to content
MappleCare Community ↗

MappleCare Community

[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″ M3 Max

Find answers from other Apple users or start a discussion about your device.

All Forum Rooms

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″ M3 Max

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
    Posts
  • #16848
    Christina Hahn
    Senior Specialist (Lvl 8)
    Diagnostic Hardware Specs: MacBook Pro 16″ M3 Max | OS Version: macOS Sonoma 14.6 | Archive Source: Apple Support Community #256564001

    I am running into a persistent issue on my MacBook Pro 16″ M3 Max 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 Air 15″ M3 (24GB) | CalDigit TS4 Dock | Kensington Orbit | Ottawa, ON
    Enterprise Mac Sysadmin & Jamf Pro Architect | "Verified Apple Discussions Archive"
    #16849
    Nathan Perry
    Community Contributor
    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.

    MacBook Pro 14″ M4 (24GB) | DJI Mic 2 | Anker Prime 27,650mAh Bank | Austin, TX
    Apple Certified Support Professional (ACSP) | Digital Nomad & Travel Filmmaker
Viewing 2 posts - 1 through 2 (of 2 total)
  • You must be logged in to reply to this topic.