Chosen Solution
Apple told me my logic board had water damage, so I decided to replace it myself. After full replacement, when I press power, my adapter goes from amber to green and then back again. Even when I tried to jump start it on from the logic board it does the same thing. Is replacing the top case my next step?
I am not sure yet if your problem is the upper case yet. Try jumping the power on pads again. This time undo the keyboard cable prior to trying it. The steps to getting to it are 1 - 14 of the iFixit A1342 Upper Case Replacement guide. If it fires up without the keyboard attached then the problem is the Upper Case. If it repeats what it previously did then the current problem is elsewhere. Are you using the 60w or 85w power adapter (magsafe)? A picture of the cable and connector on the logic board is here:
it’s probably your top cover, I’ve had the power button go out after a spill before on multiple systems I’ve repaired.
