The Peltier coils on those little units are pretty much foolproof. The cheaply made circuit boards that drive the unit are what fry. Caps swell and go bad.
I'm pretty sure that's what Derrick meant, and he's right on the ball. You should be able to find a replacement board real cheap.
As he said, you want to make sure it's not either of the fans that are fried (inside and outside). They should both be spinning when the unit is calling for cooling.
