HI , CHECK 1, THE RUBBER RING IS STILL THERE . CHECK 2 , THAT THE METAL CONNEC TOR IS STILL THERE , CHECK 3, THAT THE BATTERIES ARE INSERTED THE RIGHT WAY UP, FINALLY CHECK 4 THAT THE LITTLE PYRAMID ON THE OUTER CASE LINE UP WITH THE LOCKING RING I,E, ON THE ACCESS CIRCLE WITH SLOT IN , REGARDS...