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Quirky Macbook Pro Sudden power off issues. Battery will be fully charged, BAM!, complete power off. Reset SMC, battery now zero and will need 3 hours to recharge to 100% Unit may work well for a week, no issues. Then back to square 1. Resetting SMC will work kinda, but it’s getting old. New Battery, RAM checked and confirmed good. Unit cleaned for dust. Does not get hot, no high speed fans running. Unit functions w/o issue otherwise until it decides to throw a tantrum and start again. Yes, I know it’s a 2009 and past it’s service life. I just like a challenge and hate to toss something just because it’s quirky. Thoughts?
Given the age of the Mac it wouldn’t be too surprising some components along the current sensing circuits might be deteriorated and on the edge of tolerance specifications. If you manage to use it as it is do until it lasts, otherwise you’ll need to dive into schematics and components testing.
Let’s do some testing of that battery. Complete the guide below; upload 2 screenshots, one with the MagSafe adapter connected and another one with the MagSafe adapter disconnected. How to Test a Mac Laptop Battery
