Sound/Keyboard Issue

The sound on my laptop has recently been going on and off; it goes from muted to unmuted. Also the sound display box pops up to show that it is muted/unmuted - the sound box that pops up when you turn the volume up/down from the laptop's keyboard (by holding Fn+up)...but he keyboard on my laptop has not been working for a few months (spilled something on it).

So I'm thinking that the keyboard might be fried or a key is stuck?

Also I noticed while typing this that it occasionally backspaces while i'm typing?