Repair Battery or Logic Board?

I recently had similar behavior on a "broken" 2011 MBP that I bought.

My guess is you'll need to remove the logic board and closely inspect it for any corrosion. If you find any, use a soft toothbrush dipped in standard rubbing alcohol and gently clean it.

Another thing to look for - there are several bits of foam stuck to the logic board. When this foam is new and dry I'm sure everything is OK, but after getting wet I suspect it may become slightly conductive. I removed all this foam using pointy tweezers and jeweler's glasses (to help me see the tiny bits). I replaced the foam with some tiny bits of foam that I had handy, but I wrapped them with black electrical tape just to be sure.

If your board is like mine, there's foam just under the bottom cover next to the battery connector and there are several pieces between the board and the speaker.

I have no idea if the wet foam is your issue, but my MBP started working properly only after I removed all that foam. You'll have to be creative to replace it and hold the speaker in place.

Good luck.

Keith

ileonwhou, I'd start with a new battery first. I also do not have the "gel like substance" on my battery. May be normal, just not on all batteries. A new battery will take the guess work out of your liquid damage.