FMB920 suddenly stops sending data on certain network operators

SAV · August 4, 2026, 10:22am

As the title indicates, I have some FMB920 devices (3.29.rev18) that are connected to a private server. When I install the device and insert the SIM card, it works flawlessly…until it doesn’t. It just suddenly stops. Now, it may be related to the SIM card not having enough data, but in the next month the SIM card should have its data recharged and the GPS should continue working.

However, the GPS keeps on that last position. It does answer my SMS messages with gprs:1 and datalink:1, but the problem persists.

Now, when I insert another SIM card of a different operator and change the APN, the GPS sends the data that it recorded when it was offline and continues sending data normally. The interesting part is when I return the old SIM card and return the SIM’s APN, the GPS continues working normally.

My question is: why is this happening, and is there a way to avoid it altogether?

Ashutosh.Singh · August 6, 2026, 6:11am

Hi,

Thanks for contacting us.

Here, I suggest you update the device to the latest firmware available, which can be found at the link below:

Please note that the 04.00 series firmware comes with downgrade protection, so the device may not be able to roll back to the previous version.

Secondly, I suggest you check the operator codes with the SIM provider and add them to the GSM Operator List tab for roaming. Also, make sure the required operator codes are not added to the Blacklist Operator settings. Based on that operators, you can set the data acquisition time interval for different home, roaming and unknown mode.

Thirdly, from the GPRS Settings tab, disable the Limit Connection Error setting, reboot the device, and then check the behavior.

If you still face any issues, I am sending you the snippet for your reference.

Thanks