my renault megan reg y wont start if not ran daily been told circuit boards?

Been told the circuit boards getting wet and itd causing electrical fault. Ivw had a brand new battery .on the car but this boards making it not start and i have get it jump started. Is there anywhere I dcan.buy the board from? Not overly priced. weve dried it with hair dryer on the past but it musta gotten wet again causing more problems now must be drainibg me battery if not ran daily i havr a dead car again but the ignition lites r showing up on dashboard just my car wont start up