Can't connect to GSM networks - What's the problem ?

[Catfish77]

I am using a iPhone 5 (US/Verizon model) in Canada with a Telus pre-paid sim card and am having connectivity issues

At times it connect to the GSM network and is operational for about 24-48 hrs. Then, it either displays "No service" or "searching" in areas that clearly have connectivity.

In addition to the problems reported on this thread, I am also experiencing an additional issue - that being that the phone seems to not be able to get past the SIM unlock screen.

Specifically, I changed the default Telus SIM PIN code from 0000 to another number. when I power off/on the phone I am not able to get past the SIM unlock screen.

I have tried resetting network settings, toggling Airplane mode and soft reseting the phone to no avail

As with others, am interested to know if this might be a hardware issue or something that could be fixed by verizon, or a software update by Apple.

Also cross posted to the Apple Discussions Forum thread on the same topic https://discussions.apple.com/thread...rt=15&tstart=0

[#2]

Well considering Verizon uses CDMA and not GSM would be one problem.

[rcschnoor]

Verizon iPhones are global phone which come equipped with GSM radios for roaming on global GSM networks.

Since the OP seems to be getting sporadic GSM service, I am not sure what the problem would be.

To the OP, have you tried different SIM cards with the same result?

[Catfish77]

The Verizon iPhone 5, is a CDMA/GSM World Phone. Which means if one is roaming outside the US, the phone can connect to both CDMA and GSM network. Furthermore, as the phone is sold GSM UNLOCKED by Verizon, one can insert another carrier's nano-sim and have it work on their network to not be charged roaming charges

References of interest:

http://support.apple.com/kb/HT3939#iPhone5

A1429 - (GSM and CDMA model)

http://www.apple.com/ca/iphone/specs.html

CDMA model A1429*: CDMA EV-DO Rev. A and Rev. B (800, 1900, 2100 MHz); UMTS/HSPA+/DC-HSDPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz); LTE (Bands 1, 3, 5, 13, 25)

http://www.huffingtonpost.com/2012/09/25/verizon-iphone-5-unlocked-att_n_1909972.html

Verizon iPhone 5 'Unlocked' Feature Is Here To Stay: Carrier Will Let iPhone Owners Switch To AT&T

....The Verizon version of the iPhone 5, which went on sale Friday, came with an unexpected feature: it works on the network of AT&T and many other phone companies, as well as on Verizon's....

[Catfish77]

I've tried a different (nano) SIM card from the Operator (Telus/Canada in my case) to no avail.

I put the Verizon Nano SIM back it and it works, but that is due to the fact that it connects to the CDMA network available in Toronto. If I turn off CDMA (voice) roaming, it switches to GSM mode - and can't connect.

My guess is that it is an issue with GSM functionality in the phone. Question is, is it an issue is due to a hardware (which could be a manufacturing defect) ,  firmware or combination of both. If it's the later, a software upgrade could possibly fix things.

I spoke to Apple support yesterday and they took me through a series of steps, including a full restore. Didn't solve the problem. Likely their next step will be to replace my phone. If the issue is due to a manufacturing defect that has been corrected, then great. However, if it's not due to that - I fear the replacement phone will have the same issue.

I'll keep folks updated