Check how the cables are plugged into the t adaptor, it's easy to get them the wrong way around.
The lead from the base/charger should plug into the adaptor socket marked "App", then the "power" and "line" leads are obvious.
Another check is to switch off the handset completely, then sit it on the base. It should switch on, you will see the red led blink. If it doesn't switch on, it may be a prolem with the power supply. If there is no power to the base, you will get that message"no contact with base".
Opman