Chosen Solution
Replaced the battery and used the laptop for about 30 minutes (disconnected from power) before it shut down. Now it won’t turn on again except for a cycling of the fans at low speed- it sounds like the fans are turning on and off. I am able to get “life” from the machine if I hold down the power button while disconnected from the charger, and plug the charger back in while holding down the power button. Even then, however, it doesn’t boot to log in- however it does tell me that the CPU is working. It started cycling during one or another smc reset and nvram/pram reset. Any ideas? Thank you in advance.
Edit: coconutbatt ss added
The battery and the charging of it looks fine! I think you have a logic board issue. Lets see if the onboard diagnostics shows anything. Restart your system and press the D key. Reference: Mac startup key combinations. Let us know what you get for an error message.
