Good morning everybody, I have an LG Optimus One, originally locked to TELUS, though never used on that network. My phone started its life with Rogers after I immediately unlocked it, they are the registrar of my phone number, and last night I switched to Koodo. My phone can text and make outgoing calls, but cannot receive any incoming calls or send/receive MMS. MMS isn't quite important right now, I might have messed up the APN settings, (I have no data, what should I exclude?) but receiving calls is absolutely essential for me. Some incoming call results: Son's mobile phone: line is busy Home phone: line is busy Daughter's phone: straight to voicemail Useless SkypeOut number: 'caller unavailable', no voicemail In the case that others' calls goes to VM, I am able to access my mailbox and receive a notification whenever one is stored in my inbox. On the top of my phone's notification shade as well as on the lockscreen, the current carrier is TELUS and not Koodo. I made sure to check that the phone is running on only 3G frequencies, as TELUS no longer runs a 2G network here in Edmonton. Without having done this, I would not have been able to have any signal at all. I searched up other solutions on this forum and have tried disconnecting my battery and sim from the phone for at least an hour, as well as wait the suggested phone number porting time before reporting a problem. Anyone have any ideas? I'm hesitant about a factory reset as my SD card slot is fried and I'm without a computer for the week, so no way to backup my stuff. Thanks everybody! EDIT: New development! Though problem still persists. Tried another phone, the dial tone is heard for such a very, very, very brief second, then the busy signal is heard.