If your battery drains and is not charged for a few weeks it may not turn on. First, try charging your receiver for a few minutes. You should initially hear and feel a vibration indicating it is turning on. Depending on how of a charge is needed, you may have to keep the receiver on the charger for a few minutes before removing it. If your receiver still does not turn on you may need to perform a paperclip reset on the receiver. Just be sure to connect the receiver to the charger before resetting. If this does not work you will want to call Dexcom Product Support at 1-877-339-2664.