|I think you will find Phill that the fuzzed plug is a particularly British thing. Other than countries that have the same 230v/50Hz/13A system that GB has, I don't know of any other country that has fuzzed plugs.|
As for the OPs question. Where was this router stored during its period of inactivity. If it was stored in a cold place like an unheated cellar ,it may have accumulated some condensation. Leaving it standing in a warm environment without power for a few hours is usually a good idea.