GC3 Panel Communication Issues After Attemted LTE Module Swap

I few days ago I attempted to replace the Verizon CDMA radio module in my GC3 panel with a Verizon LTE module. After having signal strength and failing-to-register issues, I removed the LTE module and replaced it with the CDMA module. The Radio Status for the CDMA module shows registered and connected, and the radio tests all pass, but since I attempted this module replacement, outbound communication from the panel seems to fail - alarm.com has been showing a door sensor as open for the past three days, even though the panel shows it as closed. I am able to arm the alarm from the alarm.com app on my phone (indicating communication from alarm.com in to the panel is succeeding), but the successful arming response never comes back to the app and the command times out (indicating that the panel isn’t isn’t able to send the success response to the arming command). When I attempted this upgrade on Saturday, I had the panel connected to my home wifi as a secondary path, but I have since removed the wifi configuration (‘forget this network’ in network settings) to isolate the communication pathway to the CDMA radio only. I have powered the panel off for a few minutes but the communication issue persists after the panel is powered back up. The panel is running v3.1.0.5572.

Thank you for any assistance you can provide.

Note that if you are attempting to change the module your account would need to be synced with the new module id before it could register and communicate. So for the LTE module, we would need to know the serial number to associate on your account. Only one module can be linked to an account at a time.

You can submit the serial number and request a module swap via our secure message tool here.

Now, as to the CDMA module, did you perform the module swap with the panel powered on? The panel should always be powered down when making a physical alteration to its components. Swapping the module while powered can cause damage.

That said, regardless the first thing we would want to try is to send a few commands to see if we can resync with the module and reboot the panel. Would it be ok to send those now?

Yes, you may send the resync and reboot commands now.

Sent. If nearby you should notice your panel reboot. Let us know if you still do not see activity sync. Cell Tests and Pings are acknowledged right away so communication otherwise looks good.

I was able to see the panel reboot, but now the screen stays blank when I attempt to operate the panel. I can arm and disarm it from the keyfob, but there still seems to be some kind of communication issue between the panel and alarm.com; I can still arm the panel from the app or web site, but the command never receives a success response and eventually times out.

Alright, we are going to contact Alarm.com and send a few more commands here to see if we can get a response.

To verify, was the module swapped while the panel was powered?

I initially did the CDMA-to-LTE swap while the panel was powered on using the ‘radio swap’ section of the system settings menu, per the instructions that came with the LTE module. When the radio tests using the LTE module failed, I powered the unit off and re-installed the CDMA module with the power off.

I heard the panel reboot again, but the screen is still black when I attempt to use the front panel controls (I can see the LCD backlight come on, but the display is black).

Can you try powering down the panel fully, transformer first, then battery? After, please remove the cell sled. Wait two full minutes, then power up without the cell sled. Any change?

After powering the panel off, disconnecting the battery, removing the cell sled and waiting, I can now see the panel display. The panel shows ‘System Inactive’, but alarm.com still shows the panel as ‘Disarmed’ and ‘System OK’ even though it has no communication to the panel at all.

The panel shows ‘System Inactive’, but alarm.com still shows the panel as ‘Disarmed’ and ‘System OK’ even though it has no communication to the panel at all.

This is normal. Because the panel cannot update Alarm.com without a cell sled, ADC will simply show the last available status until remote supervisory signals are missed.

Let’s try powering the panel down fully again, then inserting the cdma sled again. Wait a couple minutes and power up battery first, then transformer. Any luck? Wait a couple minutes then send a cell phone test and open a few sensors.

The panel came back online and I am able to use the front panel controls. The cell phone test succeeds and all of my sensors seem to be working (the panel sounds when I open all of my doors and all of my sensors passed a walk test). There is still some kind of communication issue as alarm.com still shows closed sensors as open and times out after successfully setting the alarm. Is it possible that the panel is functioning and communicating properly but there is something wrong with my alarm.com account?

Is it possible that the panel is functioning and communicating properly but there is something wrong with my alarm.com account?

It is possible. We do see something sort of similar with another user today (though a different panel type, and on LTE.)

We’ll check with ADC to be sure and report back shortly.

There are no known issues in this case, however Alarm.com did send a few commands in an attempt to clear and sync the status of devices. Can you open and close any sensors which do not currently show the proper status and verify that they then update?

I’m not at home to try to test the remaining door sensor that still shows open, but the two motion sensors that have been stuck open for the past couple of days have cleared, and I am able to arm and disarm the alarm from the alarm.com app successfully, so things are definitely working better. I will attempt to clear the remaining door sensor when I get home this evening. Thank you for your assistance with this today.

That sounds promising. Let us know if you have any other questions!