Just got CGM - every sensor?

Just got the CGM yesterday (marry xmas) 2 days ahead of schedule. Followed the instursctions etc and when I put in the new sensor and hit sensor start it shows the grey box 80% full for the 2 hr start.

About 5 minutes later I get a ??? error and 20-30 minutes after that a sensor fail. I have tried 3 different sensors and same result. Since its xmas time no tech support until Monday, its like a kid with a new toy he can't play with.

Anyone have suggestions on fix? I have rebooted and also pushed the reset with a toothpick with no avil.


Couple of ideas - first, insert a sensor before you go to bed, connect all parts, make sure the Dex has the "i am communicating" indicator in the bottom corner, but DO NOT start the new sensor. In the morning, then hit start and the dex will go through the 2 hr start as normal. Sometimes it takes more than 2 hours for the sensor to get acclimated to you and I am finding as a new Dex user that if I wait to start I get way better results the first day.

Also maybe make sure you are inserting the sensor in an area that has a bit of a "pinch" and not in a real lean body part. That too may help.

If you get bleeding (happened one time on me, horrible bruise but was able to save sensor), wait before starting, may try "massaging" around the sensor site, just be real careful that you do not tug/massage to hard. I think that helps to break up blood, as Tech told me that if blood sticks on the wire the sensor may fail. I also used warm, wet cloths over the sensor then, and even a heating pad on low heat for about 15 to 20 min. Got two weeks out of that one even with soreness the first 3 days!

Good luck! I hear you, I just read instructions, watched video and began. Lots of time w/tech on the phone, but sure beat having to wait for appt. w/my diabetic educator - would still be waiting! LOL!

Which sensor is it?

Dexcom 7

I had the dratted ???s appear for the first time last weekend. They told me that it just is an issue communicating with the receiver and to give it at least 3 hours (if it is longer than 3hrs, they will send you a replacement!). According to whomever I spoke to Sat night, it can be caused by clothing being too tight or rubbing against it.

BTW, DexCom does have 24hr tech support. I have never had an issue during the "normal" hours. They are great. Also, if you call tech support before you yank the sensor, they do replace it. I have had mine replaced for hitting the capillary and a couple of malfunctions in the last 3 months.

Dexcom has 24 hour support. After hours you might have to leave a message/wait for a call back but don't hesitate to call them. You don't want to waste any more sensors.

There is support available over the holiday. I had to call yesterday because I had an issue. The question marks are not unusual. The sensor needs to get used to you. The sensor failure is troubling. Are you inserting the sensor correctly? I had to watch the video the first 3 times I changed the sensor. I actually screwed one up in a stupendous way. The ??? Should resolve itself in about 4 hours when the sensor gets it’s head on straight. Good luck!

Thanks for the replies I'll call them tomorrow.

I do want to be clear though, this is during the 2-hour start up. I have tried 3 different sensors, from different lots along with different sites on the stomach. Everytime it shows the 80% grey bar for the start-up, 5 minutes later ??? then 30 minutes sensor fail, either the transimitter is bad or the receiver is not going through the proper start up steps.

I have yet gotten anything to work yet

Are you sure that the transmitter is locked down fully when you place it in the sensor? I always listen for the two clicks then I am locking the transmitter down, but then I press on both sides of the transmitter once it is in place just to make sure. Also double check the transmitter id and make sure it is entered correctly.

Yep on both - Just got off the phone with tech support they quoted “they never saw a case like this before” so I have to wait for them to look at my data on Monday and hopefully figure out the problem early next week. Thanks for the help!

I’m sorry! It’s a shame that you have had so much trouble with the start up. It is all worth it in the end!!!