Just wanted to share my solution as i could not find anything when searching that came close to solving my issue.
TV is a UE48H6200AWXZF Smart tv.
Issue developed after connecting to Wifi at a new Address, Tv was in service using a Google Chrome stick and worked perfectly up until this point. Previously tv was connected to wireless and functioned normally with a Chrome stick and a Firestick attached by usb ports.
In the end i tried all the options of force restart and indeed dismantled the set to check continuity of connectors etc all to no benefit.
I had a conversation with a samasung customers service girl in the Phillipines, She suggested the following ;
Downloaded samsung software for the set via the updates page on the samsung website and placed the file in a usb stick, install in the set and cold start it ! Voila! the set became responsive to the handset.
Thereafter it was a case of reconnect to wifi and then give the set a software update.