Chosen Solution
Hello!Was an extremely happy owner of MBP 16" A2141.2 Months ago became an owner of A2485. I do have the bad habit of not Shutting down the computers I just closed the old one and put it under my bed. As it’s a great dust collector I decided to give it to my parents however for my big surprise it’s not turning on.Initially I thought that the battery is drained so I left it connected to the genuine 96W charger overnight.On the morning I didn’t have much luck as the A2141 still doesn’t have any signs of life.I tried different cables and made sure that the charger is working (by connecting the new MBP) and different USB ports.So I started my investigation: Reset the SMCReset the NVRAMOpen the bottom of the MBP- clean the dust- check the batteries (look fine)- disconnect the battery- press and hold the power button for 10sec- connect the charger and press the power button Unfortunately no luck. There wasn’t a single movement of the fans, noice from the speakers or light from screen :-( From what I understand there should be a faulty Logic Board.The machine is out of warranty (that’s why I did step #3 of the investigation).1.5years ago I spilled a bit of water on the MBP. Turned it off immediately and wasn’t using it for 3 days. On day 4 it was working except the screen, however it wasn’t an issue for me as I’m using external screen. For my biggest surprise the screen turned on 2 days later.Since then I never had any issues with the machine. After opening it I noticed a tiny erosion (marked on the image) which I cleaned with alcohol
Ordered an USB C Power Meter Tester to check the power. Wanted to ask for some advice what I should look for as a possible reason for this faulty machine? I’m pretty handy guy and finished an electronics schools (15 years ago and haven’t practices much since then as I focused on Software) so more than happy to dig and try to fix it myself (happy owner of the ifixit pro tech toolkit).
At this point I’m suspecting you have a dead battery either because of the corrosion damage and/or being left for so long in sleep mode. While the USB-C power checker will help in seeing if the charging logic is even working it won’t fix the dead battery. I would just bit the bullet here getting a replacement battery MacBook Pro 16" (2019) Battery, then carefully plug it in (leaving the original one in place) so you can check the charging logic using this gem of an app! CoconutBattery take a snapshot of the apps main window and post it here for us to see Adding images to an existing question it will show you what your USB-C power adapter is doing. As the shipped battery will only be partially charged your system should be charging it. If not you’ve proved you have a logic board issue besides the battery.
You have to use Apple Configurator from another mac computer while connected to the forward usb-c port on the left side of the offending macbook. Put it in DFU mode and “revive” from Configurator on the working macbook.
