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Hi all, Looking for some assistance hopefully. I purchased a 2nd hand MacBook Pro 2011 A1278 about 8 months ago. Everything worked fine with the laptop for months, about 2 months ago the laptop suddenly stopped charging the battery. The laptop can run from mains power alone (disconnect battery and power on) The MagSafe charger light goes Green when plugged in. The MagSafe charger light does not change color when plugging in (with battery connected). The system can run from a battery that holds charge, it just does not charge it. I replaced the battery with a newer one as the stock one was near the end of its life and said service battery, I suspect the battery i purchased although claimed it was genuine OEM damaged the Logic board. I purchased a 3rd battery to double check, the laptop ran fine from the battery but would not charge it. I have swapped the DC board to see if that might be the problem. But didn’t fix it. I have a copy of the Apple service manual and also open board so I can find the relevant resistance values etc. Reading other forums it seems it could be a problem around the U7000 chip and the resistors for battery sensing etc. I have read the following resistors: R7011 - 1.3, should be 9.31K, it also has ground both sides so shows this is gone I think?R7010 - 30k correctR7013 - Missing ?R7012 - 1K correctR7015 - 100K CorrectR7086 - 332K correctR7021 - 10 correctR7022 - 10 correctR7025 - 0.2 (close enough)R7052 - 9, should be zero?R7051 - 2.5 close enoughR7001 - 4.9 close enoughR7000 - 0.2 close enoughR7002 - missing?R7016 - 3.01K correctR7005 - 137.6 should be 20? So I have 2 that are missing from the diagram, then 3 that are reading different values. Are the 3 resistors that have wrong values linked at all you think? I’m apprehensive about purchasing the soldering equipment and resistors if there could be a greater problem here. Wondered if anyone would have any advice to give or other things to check whilst I’m at it? I have also attached pic of the battery info in Apple System info. Any help would be greatly appreciated.
Measuring resistors like you’ve done is not how I work out charging problems. I focus on voltage measurements on the power rails. Once I’ve identified power is getting to the logic board correctly. Just like opening the water tap and not getting water at the sink we need to locate the pathway back to the water main. Here its just easier to start at the main (MagSafe) and trace the power from there. Once I know which rail is faulty I can then dig into the circuit which could be damaged MOSFET’s which is the components that alter the pathway for power to go through. Either going to the battery to charger it, of from the battery to the logic board to power it. Yes! A bad battery can mess things up! Which is why I need the CoconutBattery and we need to make sure the MagSafe charger is really good. Update (04/20/2020) Looking at the screen capture I see two issues with the battery values are wacky! Amperage mA -272 & voltage mV 10853. I also see the charger is connected and its not charging! This looks like you have both a bad battery and your charger maybe bad as well or the charging logic within the logic board is damaged.
