Macbook trackpad won't click
I bought a Macbook Pro with Retina Display a little over a month ago. When I bought it, the trackpad could physically click fine, but I changed the settings to "tap to click". Today I tried actually clicking and the trackpad barely presses down and I can only hear a very faint "click" sound. I'm fairly sure that the trackpad could click fine yesterday.
I use my laptop almost every day for at least several hours. I do eat sometimes when I'm on my laptop but I don't think anything could get under the trackpad, could it? What do you think the problem could be? Thank you!
MacBook Pro with Retina display, OS X Mountain Lion (10.8.3)