Base 1 Flashing on handset (BT Diverse 3010 Executive )?

Have tried to register to base to no avail. Since no (usual) beeps are heard when handset is replaced on base and it won't charge, I'm no wondering if there's something wrong with the power adaptor. Additionally when page button is depressed no beeps either. Will phone actually charge even if not registered with base.

Have checked cable and can't see any damaged areas and obviously changed plugs. Even though old this phone has always been reliable. Also all this happened fairly suddenly!

Many thanks in advance for any help. Really need to get this phone back on track asap!