Help Replacing Motherboard

Sounds like it. I'm not sure what else it would be.

The only difference in motherboards for the same model would be the CPU and GPU (if any). So you can put an i5 Mobo in your MacBook Pro, it doesn't have to have an i7. Just make sure you're getting a mobo for the model year (ie Mid 2010) and screen size (ie 13").

The battery, touchpad, keyboard, SuperDrive, etc. will all connect like it was your old motherboard.

In theory, the water could have damaged other components as well, so I can't say "oh just get a new mobo and your MacBook will be 100%!"


EDIT: I didn't catch that it works with external displays... Still, you spilled water on the thing, and the mobo controls the built-in display... So I think you'd need a new mobo anyway.

 

The logic board might be toast, it might not.

So just to make sure, you are able to get the machine to start up, and you can produce video when connected to an external display? It is possible you just have corrosion on the LVDS connector where the internal LCD connects to the logic board. I commonly see corrosion there in system where liquid damage is present. Go to your local hardware/electronics store and look for electronics cleaner. It's stellar at removing corrosion. Wherever you see corrosion on the logic board, hit it with some cleaner and gently brush with a toothbrush. I've had a lot of luck bringing systems back from the dead by doing this.

After you clean the board, perform a SMC reset and a NVRAM reset.

If cleaning the corrosion is unsuccessful, there is still a possibility the logic board hasn't failed, inspect the LVDS cable for charring or damaged pins. If the pins on the cable are damaged, you may need a replacement LCD/Clamshell as well.

You might be able to shoehorn an 09 MLB in there, but it isn't worth your time. The board layout between the i5s and i7s will be identical on the Mid '10 board, so pick whichever you can afford.

The most important thing to remember while attempting any repairs is to minimize ESD damage, so be sure to do any repairs properly grounded.

If all else fails, or if this feels too ambitious for you, I'd check out Microreplay. In situations where we've been unable to fix a board, but don't necessarily want to replace the MLB, we send our boards there.

I'll PM you some additional information if needed.