Solder melting point is something like 300 deg C so you are not going to reflow joints in an oven. Even if you could get it to the melting point of solder you'd more than likely damage some of the components.
All you'll do by putting it in the oven at a low temperature is drive out any moisture that may have got behind any of the components
All you'll do by putting it in the oven at a low temperature is drive out any moisture that may have got behind any of the components