This is one of the best places in the uk to get your nexus 7 screen repaired ;) http://www.repairsuk.co.uk/tablet-repairs/google-nexus-repairs/

If you are based in the UK there is a company that i used to repair mine, they used some sort of board cleaner to get mine working again and it only cost me 20 quid :) http://www.repairsuk.co.uk/asus-nexus-7-repairs