No light on magsafe, and MBA not turning on

I've got a late 2010 MBA 2.13GHz model A1369 which no longer boots up.

Problems:

• No light on the magsafe, not even dim.
• MacBook Air doesn't respond in any way to trying to power on. The battery should be fully charged, as it was plugged in, green light, and working until I turned it off.
• Audio port not working with any audio jack (before the computer stopped working altogether).

I've tried:

• Different power adapter
• Different power plugs
• Cleaned the male and female magsafe plugs

Backstory:

A few weeks ago some water spilled on the table the MBA was on. Not directly on top of the keyboard or anything, but enough to splash some water on the back of it. I immediately shut it down and left it to dry.

Then this followed:

• A couple of days later the Air wouldn't go to sleep when shutting the lid. I had to manually set it to sleep before closing the lid.
• Plugging in headphones didn't do anything, the sound would continue playing through the Air's speakers. Tried with different headphones.
• I could not boot up the computer unless the power was plugged in.
• It wouldn't charge, the magsafe light wouldn't come on.
  • I fixed this by cleaning the dust and gunk out of the female magsafe.
  • The light on the magsafe was extremely dim until I turned the power on.
• Ran Disk Utility and fixed all the permissions (I think it was).
• Upgraded from Mountain Lion to Maverics in the hopes that it would fix the audio problem. It didn't.

So basically the laptop was working fine for a few weeks besides not going to sleep when closing the lid and not being able to use headphones. Until today.

My question

I think I have the same problem as mentioned in the post No Power, Not Charging and that replacing the I/O board will fix it.

But I'd appreciate having my suspicions confirmed before going ahead with it. Am I right or wrong in replacing the I/O board?