Solving the dread ? issue

I have had my unit since January 2011.

When it works - great.

A number of times I would get the ??? symbol - sometimes when operating and other times when in the 2 hour startup. Discussing this with Dexcom seems utterly useless.

What I suspected was that turbulence in my body BG was upsetting the soiftware in receiver
and for reasons undocumented the receiver gives up and declares ???.

For the first time 3 times in a row I was able to get unit back up on same sensor that did not seem duff.

First I stopped the sensor.

Then I watched my bg with hand stick machine every 15 minutes to make sure that the tubulence had settled down and was back running stable.

Then I restarted sensor and watched over the 2 hours as wel las monitor BG on fingerstick to see if readings stable under 200 199, 166 to 133.

After 2 hours and with machine/sensor stable and asking for initial cal; I entered two readings from finger stick and receiver sensor started up and ran fine.

I also suspect that as sensor ages, its dynamic range drops coupled with tricky software doing I know not what and one gets ???.

This is first time I have found way to restart sucessfully three times in a row sequentiallyon a sensor still apparently working ok.

Thanks for this info! I have been having some issues with ??? during start up too. One thing that has seemed to help me with that problem, is to let my transmitter and receiver sit next to each other for 5 minutes before starting a new sensor session. I guess it actually says to do that in the Dexcom manual, but I hadn’t been doing it and had been getting lots of ???s. Now that I’m doing it, it seems to be working much better! I have heard that starting up a sensor session when your blood sugar is stable makes for an easier time of things too. Thanks for the info!

Thank you so much for responding.

Here is some other thoughts you may want to look into:

a) watch out where your receiver/probe are and any blue tooth servers, wireless gear and your lap top.
They can absolutely jam your dexcom receiver and leave it stuck on prior readings. Usually home is worse for interference while in car on back side of sierra’s in California will run for hours without hitch.

b) I try to restart/ new sensor in morning and dread doing at night before bed.

c) morning can be tricky as liver system all starting backup and can cause turbulence . I would wait an hour after wakeup and any shots to restart/change sensor. I got caught on that as I retarted too early and body turbulence upset receiver software.

d) night time before bed is worst time and I hate and try to avoid. Starting in am gives one all day wide awake watching monster restart and get rolling.

good luck and thanks for reading.