Sonicare HX8910 make a buzzing noise when charging, 2 buzzes then 1

When i put my toothbrush on the charging unit it make a buzzing noise 2 buzzes the 1 and it does not seem to charge.

I have open the unit and cleaned the inside and let it dry whilst open - but the problem still occurs

crwdns2893858:0crwdne2893858:0 crwdns2893862:0crwdne2893862:0

crwdns2894050:0crwdne2894050:0

crwdns2889612:0crwdne2889612:0 1
crwdns2892346:0crwdne2892346:0