Y key doesn't work.

Apple's keyboards are pretty weak and mushy, likely the little air bubble has burst so the entire keyboard will have to be replaced.

In fact I refuse to use their keyboards, trackpads or mice at all, they make them cheap and inferior, especially for large men or those used to clicky clack type keyboards where one drives the keys home to get a audio response.

If your under the one year warranty or 3 years with AppleCare, then take it to Apple and they will fix it for free.

If not under free care, then get a estimate from Apple, also you can search online for Mac repair and they can fix it as well.

Make sure to file a complaint too.

Check

One or more keys on the keyboard do not respond

<http://support.apple.com/kb/TS1381>

I had the same problem with my o key. The i key would also stick on startup. SO, after a few unsuccessful attempts to get it working, I ordered a new keyboard.

In the meantime I shut down my iMac and unplugged the keyboard. After two days, I came home to find my roommate had turned it back on and hooked everything back up to watch DVDs. My keyboard is now mysteriously working again. She said she didn't do anything to it. She never tried the keyboard, because she was just using it to watch DVDs

Don't by a new keyboard right away. It might start working again.