Cleaning the contacts in the single base and the charger/amplifier will help in charging of the pager. A minor amount of dirt buildup will effect the amount of volt/amps that is going through the pin to the contact on the pager. The charger and the pager communicate to determine the charging algorithms. Use an eraser from a pencil and apply light pressure on the contact and in a circular turning motion, will clean the tip of the contact. Do not go back and forth, which could bend the contact. Clean out the charger base and place the pager in the charger base.