Condensation doesn't mean water leak necessarily. If you are in a cold area, and your amp is running, it will form condensation. Outside COLD VS inside HOT. My advice to you is to replace it. AMP's are so difficult to identify what component is burnt out, unless you take it to a specialist. Either way the only DIY you can do is get a new one. Sorry mate.
**Working PART-TIME for Carjunky for a while, Please bare with me =)**