ReadyNAD Duo know longer visible on network

Evening all, apologies to anyone waiting a response to help with similar issues. Looks like I have managed to get to resolve the problem although I couldn't swear how or why it is solved. After resetting routers, protocols, opening ports with no effect I removed one of my HDDs with the intention of factory resetting my ReadyNAS. I ran out of time and put the HDD back in just for convenience sake which forced a re-sync and hey presto the ReadyNAS is visible again to my PC and DLNA TVs. I could speculate as to why but it really would be guess work so I'm going to leave that to others. Thanks StephenB for suggestions and help along the way.