[Samsung Galaxy Nexus] JLishere:
I need a second opinion about the radio on my Galaxy Nexus. Help!

Context

I recently switched from the GNex to a Nexus 4. I wanted to give my old GNex to my sister, but the glass was slightly cracked from a fall a couple months ago. So before giving it away, I decided to purchase a glass/digitizer from eBay and replace it myself - the part was something like this. The process involved taking apart the frame from the digitizer/glass - which some of you know are fused together. Everything went well (or I thought so).

The new screen works, and I gave the phone to my sister. She popped in her SIM card (we're both customers of Fido in Canada). But she's now having problems getting the GNex unto Fido - actually, she can't see any network signal at all.

Screenshots / Symptoms

1. Lockscreen says "no service"

2. In Mobile Networks > Network operators, I can see the phone searching for available networks, but after 20-30 seconds, it just returns a blank list (no network displayed)

3. The baseband is correctly displayed in the About menu (i9250XXLJ1).

4. Under Status, the network is shown as "Unknown", mobile network type: "UNKNOWN:0", service state: "Out of service", and Mobile network state: "Disconnected"

5. The IMEI or phone number seem OK.

6. I went into the Phone info menu (*#*#4636#*#*). [ image 1 ] [ image 2 ]. Current network is blank. The signal strength feels weird (can anyone confirm if that number makes sense?).

7. Not sure if that's related, but I installed GPS Test and unable to get a GPS lock. It could simply be that I have no mobile signal in the first place, but Wi-Fi works fine, so shouldn't I be able to get a GPS signal anyway?

Here's what I tried so far to fix it:

1. Reboot / Battery pull: I did the usual reboot, battery pull, as well as toggling Airplane mode on and off - no dice.

2. Sim card: At first I thought maybe we needed a new SIM card, but it works fine when I insert it in a different phone (Nexus S). I also haven't seen any error message pertaining to the SIM - just "No service". We also tried another friend's SIM card and still seeing "No Service". So I don't think the SIM card is faulty.

3. Checking with carrier: I called our network carrier (Fido) and they're not seeing anything unusual on their end. Account in good standing, and as I said before, I can use the SIM card in an older Nexus S. I also made sure that the IMEI number wasn't blacklisted, which it doesn't appear to be. At this point, I'm confident the problem lies in the device and has nothing to do with network or coverage.

4. Cerberus anti-theft app: This one I'm unsure about. Before all this happened, Cerberus was installed on my GNex. I set it up so that unauthorized SIM cards would be reported to my email. When we swapped SIM cards, I got the expected warnings from Cerberus, which I ignored since I was the one who did the switch. But after experiencing the problems with the network, I went back to my inbox and noticed some emails displayed the Network operator as 302720 (Fido), and then some would show 0000 () - see the screenshot, the emails are just a few minutes apart but show different network data. I find that odd. Is there any chance that Cerberus may have messed with a setting and blocked the SIM card from the device? However, I did wipe the device and flashed back to stock. I also re-installed Cerberus and made sure my sister's SIM card is registered as authorized. We're still seeing "No service".

5. Factory reset / Flashing to stock The phone was previously rooted and used to run Paranoid Android v3.65 before I replaced the screen. I never had signal issues on that ROM. To make sure it wasn't the ROM or Cerberus causing the problem, I did a factory reset. That didn't fix it. So I flashed the phone back using Google's factory image (takju 4.2.2 build JDQ39) - completely back to stock, including bootloader, baseband radio-maguro-i9250xxlj1.img and a full wipe. Even on stock, I get the same results as shown in the screenshots (no signal, no mobile network).

6. Radio settings (*#*#4636#*#*): The last thing I tried to do is modify some of the radio settings: turning radio on and off, rebooting. And trying a different preferred network type (GSM Auto vs. WCDMA, etc). None of these worked. It keeps defaulting to WCDMA after a reboot, but I don't think that would prevent me from getting a signal (on the Nexus 4, that's exactly what I'm seeing, and it works on Fido).

I don't know what else to do. At this point, I think it's gotta be a hardware problem. Perhaps something went wrong when I manipulated the frame (the speaker/radio module at the bottom)? I also think that it's the modem (and NOT the SIM card holder) that I need to look into. My last resort is to purchase a new antenna off eBay and attempt to replace it in a couple days. I'm desperate and really hoping that can solve it.

In the meantime if anyone has a second opinion or suggestions, I'd be so grateful!!!

Is there anything else I can try or may have forgotten about?

Thanks!