Chosen Solution

It’s a MacBookPro 15” mid 2015. After I turn it on, I can hear the “starting” sound, and I can see the splash screen, and the touch pad works, but it only lasts 2-3 seconds, and then it turns off. All that only happens when “on power” - the power is connected, and the green light is on on the connector. If I disconnect that, then the computer will not turn on at all. When it’s on, I can see the battery sign with the exclamation point in a triangle. Picture attached. I suspect the battery, but not sure if that’s the problem. All that started when a cup of tea was spilled on the computer while it was on. I took it apart today following the guide at this site (MacBook Pro 15" Retina Display Mid 2015 Battery Replacement ) , to see any liquid, or damage inside, but didn’t see anything “interesting”. I successfully put it back together, and the symptom remains. Any advice will be highly appreciated.

You’ll need to go back in and take the logic board out as the spill more likely is on the backside of the logic board MacBook Pro 15" Retina Display Mid 2015 Logic Board Replacement, Look for corrosion and/or stains.

San Diego Mac Repair  is the answer! Highly recommend to anybody in San Diego, if you have Mac problem! Got my problem fixed within a day, for $160. It was “just” the battery that needed to be replaced. Note - the quote from Apple “Genius Bar” was $1475 for a “Flat rate liquid damage repair”! Thanks again for the lead, Dan!