OTA failing on electron running 3.3.0 on third party sim

I am having trouble doing an OTA as follows:

Device is an electron running 3.3.0 in a remote location using a third party SIM.

I am visiting the site shortly so decided to test OTA functionality.

The first time I tried this, the device was running 2.1.0 and the OTA updated the OS to 3.3.0 as well as application firmware. This ran first time without a hitch.

The device is now running the new firmware, publishing events, responding to remote calls and diagnostics calls.
Diagnostics report a cellular signal of 30%-40%.

I have tried about 20x to do an OTA and it always fails.

OTA works fine on a local test device. The only difference apart from signal strength is I am using different third party SIMs.

Is there some firmware change that could be affecting the conditions allowing an OTA update to proceed?


Could you log at ticket at support.particle.io with the Device ID?

The most important thing when doing a Device OS upgrade of an Electron with a 3rd-party SIM is that you need to make sure the cellular modem is never powered down before the upgrade is complete. If the modem is ever powered off completely it will lose the APN and no longer have cellular connectivity. But it also cannot boot to set the APN because user firmware doesn’t run until all dependencies are met in safe mode. But the dependencies cannot be updated because the device doesn’t have cellular connectivity.

This is not an issue with the Boron, B Series SoM, and Tracker as they store in APN in flash so the APN is set even if the device boots into safe mode.

Many thanks for further explanation and Catch-22 cautions.

I previously did an OTA update that succeeded (which included the incorrect APN as it happens), but luckily as you explained here this did not take the electron off-line as the device has not been powered down and the modem has not been hard reset and continues to use the previous (correct) APN.

Now I cannot perform further updates to correct the APN error (even though the device is working perfectly otherwise) and so should the device power-down, it will take it off-line!