Strange CGM behavior

Just changed it out 6 days ago and it was working great up until 2250. It cut out and it hasn’t turned back on yet…question marks since 2250. Haven’t ever had one cut out so early before…do you guys think I should just hold out a while and see if it reconnects? The sensor/transmitter look great - untouched. Nothing visibly wrong with it at all.

Update: I’m thinking I’ll just wait a couple hours at a minimum…but I can’t go to sleep and not have a working CGM. I’ve been spoiled.

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G5 - right? I would pop the transmitter, wipe it with alcohol (let it air dry) then pop it back in and see if it picks up.

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If it doesn’t come back on by 0050, I’ll do that. I’ve never had this happen before in the 1st week…usually it’s well into the second week. Thx for the recommendation!


Sometimes I drink more fluids, and the ??? goes away. Or could be coincidence.


@ClaudnDaye, we see that often before 7 days unfortunately. With us, once you start seeing it, it is almost always s sign that the sensor will die soon. The only exception for us is if it is due to dehydration, as @MM2 mentioned. So the moment we see this we drink tons of water.

Once you start seeing the ??? show up, it will often appear again, more and more. Then it is a question of when you cut your losses. If you see the sensor becoming noisy when it comes back, it almost always means, for us, the writing is on the wall.

I’m G4 but I see that almost daily in the last week or so of my sensor life (avg abt 6 weeks). For a while I’d do what @Thomas said – pop out the transmitter and wipe with alcohol. More recently I’ve become a fan of giving it a couple of thwacks with a wooden spoon. It’s usually reading again within 15 minutes. I’m using a refurbished transmitter, which is slightly bulkier than a sleek direct-from-Dexcom one, so I’m thinking it just needs a little realignment in the seating. (I’m just continuing a tradition. My Scottish grandmother used to realign me with a wooden spoon, too.)


“Come here, Liam…”

…Liam walks into the room, looks then turns and runs, yelling “Not the wooden spoon! Please papa, not the wooden spoon!”


Sorry, I forget how young he is. Maybe a Fisher-Price hammer instead?:grinning:



Just call Dexcom tech support like I did 2 times a week for 2 months straight, like I did :rofl::joy:. They will help you troubleshoot the issues and replace the sensor.