We have been using our loan Dexcom since Jan 17. We haven't got 7 days out of a sensor yet. The first one failed after 2 days of accurate numbers. The 2nd we had to remove because the receiver died. This sensor has lasted 4.5 days and is now in the shutdown phase. It was very accurate during the day but not so good (said good BG's which didn't match with higher meter BG's)at night. Now half way through the night the screen has started greying out. Should we try restarting this sensor? What causes this? Any other options?