2gig GC2e panel refuses to connect

I originally had a GC2 panel installed by Vivint in 2012. In 2018 I got a takeover kit and switched to another Alarm.com provider. At this time it had an AT&T 3g modem. I never had any connection problems with it. None. Never.

Then on June 16 we had a power outage that lasted a couple of hours. The backup battery never fully drained but when the power was restored, after about an hour, the panel warned that the radio could not connect.

The consistent symptom is that when the panel boots and I go into the radio status menu, I can watch the radio power go from off to on, and then after a few seconds, the IMEI and Subscriber ID both appear, and it immediately says “registration denied.” Connection status “Idle.” Signal strength is typically around 13/31 to 18/31.

I went several rounds with the security provider support. I’ve lost count of how many times I’ve power cycled, etc. They suggested I needed an LTE modem so I bought a new AT&T LTE module and installed it, but it didn’t make a difference. Then they suggested that maybe the power outage damaged the panel so I bought a brand new GC2e panel.

I installed the new LTE modem in the new GC2e panel and upon first boot it connected instantly and even (magically) restored my settings and sensors from the previous GC2 panel within moments. A very pleasant surprise! I thought I was done, but an hour later, I got the connection failure error again. Now the new GC2e panel is doing exactly what the GC2 panel was doing–registration denied.

I’ve tried factory resetting (both panels), numerous power cycles, moving the panels to different areas of the house, nothing changes. Yes I have confirmed that the LTE radio antennae are connected and routed properly. Yes I’ve tried removing and reinstalling the cell module (powered off of course).

After the security provider told me there was nothing else they could do, I thought maybe a change of scenery would help. So I canceled that account, opened a new one here, and started the setup process. But guess what? Same thing. Even after factory resetting the panel and waiting at least 30 minutes, within seconds of boot, the radio immediately jumps to registration denied. I can’t login to Alarm.com because it says it hasn’t received a signal from the panel yet.

I feel like I’ve ruled out any hardware problems on my end. New modem, new panel, I even used the new DC power supply and fresh, new power wires instead of the wires in the wall. Signal strength of 13-18/31 isn’t perfect but I would think it should be sufficient. My cell phone is on AT&T and it has no problems maintaining an LTE connection. Besides, why would it suddenly refuse to connect via AT&T after 10 years of no problems?

Another thing that I found strange is that the panel reports the same “Subscriber ID” number, even after factory reset, and even after switching to Surety. I haven’t been able to confirm what this number represents but I had been assuming it is tied to the Alarm.com account somehow and is fetched from the upstream connection.

Before I canceled my account with the previous security provider, I thought that the two panels displaying the same Subscriber ID (even after a factory reset) meant that the panel was establishing a connection, attempting to provision, and being denied by the network for some reason, but that part of the response received by the panel included the customer account number associated with the IMEI (Subscriber ID). So I expected that after switching to Surety, I would get a different Subscriber ID. Yet even after switching, that number is the same as before. That makes me think that either I’m wrong about what the Subscriber ID is, or something is very wrong on the upstream side.

I’m beyond frustrated at this point. One of the main reasons I switched to Surety was this active support culture. I’m hoping you can work some magic and help me get this thing functioning properly.

What is the firmware version on your panel?

I apologize if it is above, but I am not seeing any reference to a cell phone test. You’re going to see registration denied if your module is not connected to the network and a cell test is necessary to do so. Ignore the stuff on the radio status page for now and just run a cell test. What is the result of the cell test? Let me know any specific error message results that you see when running it.

Do you by chance see a “PUK locked” message when running the cell test?

Thanks Jason! Firmware on the GC2e panel is 1.23. On the GC2 panel it’s 1.19.3.1. You’re right, I forgot to mention cell tests. Yes, in every instance I run a cell test. Each time there is a series of messages saying: “Acquiring network registration. Please wait…” After about 30 seconds it says something to the effect of “Modem timed out. Please try again later…” and below that, “The Cell Phone Test failed.”

I don’t ever recall seeing a message saying “PUK locked.” On the radio status page it says “Sim Status: not locked” if that helps.

Just to be 100% sure, did you use both of the new antenna for that module? The old 3G antenna cannot be connected to one of the ports for the 4G LTE to function properly.

What is the exact model number of that module? Would you mind sending a photo of the device label as a private message?

Yes I used both of the new antennae for the LTE modem. I did not try to reuse the 3g antenna on the LTE modem. I have also tried reversing which LTE antenna is connected to which port on the module just in case, but it does not make a difference. In every case I have ensured that each antenna is fully seated and snapped down.

I will certainly PM you a photo of the device label, although it will be a few hours before I will be able to access the panel.

Related question in the meantime: There is a micro USB port on the LTE modem. Does anyone know what this can be used for? More specifically, can it be used for diagnostic or debugging purposes?

Not aware of any user-available diagnostics.

The likeliest causes for what you are seeing are probably one of the following:

  1. Bad module. It happens, rare and not usually my first guess.

  2. Carrier may support LTE in that specific area but signal may be roaming through a different carrier’s tower. AT&T and Verizon use third party infrastructure in some areas, and while that is usually not a big deal, it might be causing a problem with registration.

  3. Activation of that module may have been interrupted when it was first installed, and it may not be able to provision properly. Try the following steps:
    Enter the installer toolbox on the panel. Start and immediately cancel 3 sensor walk tests in a row. After the 3rd cancel, quickly run a cell phone test. This test will fail. After it fails, wait at least 10 minutes, then run one more cell test. Any change?

Thanks Jason. When I get home in a couple of hours I will try the walk test trick and will also send you a photo of the cell module.

Just in case, it may also be a good idea to try updating firmware to the latest 1.24 for the GC2e. Download it here for the update cable.

Oh excellent. I didn’t realize 1.24 was out. I’ll update it tonight.

I’ve flashed the GC2e to 1.24.

I performed the walk-test trick but nothing changed. I actually had to add a sensor to the system first so it wouldn’t immediately complete the walk test. I started then immediately canceled the walk test three times in a row and then immediately ran a cell test, which failed as before. I waited 20 minutes then performed another cell test. It again failed in the same manner as before.

This was the point at which I flashed the firmware to 1.24. Then I tried the walk-test trick again with the same results. I am about to PM you a photo of the cell module label.

Alright, unfortunately that is suggesting that this module will not be able to activate properly. The best bet, to rule out both of the most likely issues, is to try replacing that with a Verizon LTE module instead.

Was that module new or used when purchased? Was it from a security products vendor online?

Also just in case, how long is the power cable for your panel and what gauge is the wiring?

Did you reuse the same power supply from the first panel, or did you switch out for the plug in power supply that came with the new panel?

The module was purchased new from buy2gig.com. I’m not sure exactly how long the power wire run is, but I would ballpark it at at least 50’ in a straight line. It’s 18-gauge 4-connector alarm cable (red sheath). I did reuse the existing power supply from the GC2 panel when I installed the GC2e panel, but only after confirming that it’s rated for the same voltage and current as the one that came with the GC2e, and measuring with a multimeter first to make sure it was delivering +14V DC at the panel side.

As mentioned, the GC2e initially connected and provisioned immediately, and even restored the previous panel’s settings and sensors. After it inexplicably lost the ability to maintain that connection within an hour or so, as part of my troubleshooting efforts, I tried swapping out the power supply for the one that came with the GC2e, and also tried using a much shorter 12" length of 16-gauge wire. That was also how I made the panel movable so I could try relocating it to various different places in the house.

I’m not opposed to trying a Verizon cell module, but would it be returnable if it does not resolve the problem?

It is possible that the original power supply was damaged and may have affected the new panel, but that’s quite a stretch, and I would expect to see other indication of impacts, like the sensor radio failing or the module being unrecognized by the panel at all, not simply failing to connect to the cell network.

I think it is more likely the module is bad or carrier network/towers are causing the issue.

I’m not opposed to trying a Verizon cell module, but would it be returnable if it does not resolve the problem?

Yes, products sold through our store have a 30 day return policy. Be sure to hold onto the box and all included items in case it does not resolve the issue.

I’m sending you a PM to a module without the extra bundle parts in the store.

I received and installed the Verizon LTE radio, and it’s working great! Thank you!

Incidentally and FYI, before I signed up for service with Surety, I ran the IMEI of the AT&T module through the “Can I activate my equipment?” page, and it reported that it was unable to find the number in its database. I sent a support email asking about this, and the reply said:

Thank you for reaching out! I can confirm that some of the newest modules are not being accurately reported via the Alarm.com module check tool at this time. Our IT team is investigating this issue with Alarm.com.

In the meantime, I have checked your IMEI [XXXXXXXXXXXXXXX] and it looks like that is an unregistered module and you should be able to activate service without issue. Simply skip that module check step and you can choose your plan and proceed to purchase and activation!

I have to assume there’s a relationship between the module check tool failing and the module being unable to connect.

I have to assume there’s a relationship between the module check tool failing and the module being unable to connect.

The Alarm.com API behavior with some module validation has been seen on working modules. The failure of your AT&T module is coincidental.