Chosen Solution
Hello, I have a mid 2015 Macbook Pro. Recently it shut down mid use. After that it will get to the black apple loading screen and just shut off. When I try booting into recovery mode or diagnostic mode it also shuts down. In diagnostic mode I can select a language, it starts to run, and then powers off quickly before doing much. My battery is in poor health (2000 cycles, service recommended). I disconnected the battery and attempted to boot but found the same issue. I then learned from the helpful folks here in another thread, that mid 2015 macbook pros are unable to boot without a battery. I also found that if you disconnect the trackpad connector, due to less power being drawn you may be able to get around this. I disconnected the trackpad connector, plugged the battery in, and was able to successfully boot (albeit with fans at 100% and CPU underclocked as expected). I then unplugged the power cable and the laptop continued to run on battery power. I’m suspecting I need a new battery, but the fact that it ran on battery power w/ trackpad disconnected makes me suspicious. Does this sound like battery is root cause or some other component? Thank you for your time
So while you do need a new battery from what you state. It’s also likely your trackpad needs replacing too MacBook Pro 15" Retina (Mid 2015) Trackpad this series is a bit more susceptible to liquid damage as the circuitry is a bit exposed. I would inspect the trackpad for corrosion damage So I would dry fit the battery test again and only after you are sure then glue the battery in.
