I have a number of faulty handsets (typically screen faults) which I cannot track the supplier or purchase date for. They are not under maintenance cover. Is there a way I can determine the manufacture date from the phone to determine whether it is likely to be under warranty ? How are handsets tracked by CISCO - can they verify it themselves ? or can I lookup this info myself based on MAC/serial ? How should I attempt to get these replaced/repaired under warranty ? I am based in the UK.