"Not registered on network"

[jhsparky]

I had a Telus iphone4 with a Telus sim, never had a network issue. I then put my Telus sim into an unlocked/rooted Galaxy SGH-i727 (skyrocket) OS ver 4.1.2 and randomly get "not registered on network" or 1 bar. This happens if I cross a street and even if I move from one end of the couch to the other, at one point I changed APN settings and did notice a very small improvement with registered-not registered issue (now reconnects on its own). Then after trying dozens of other suggestions I popped my sim into an unlocked/rooted Galaxy GT-s7560 and never had an issue. I prefer my SGH-i727 mainly because of size and speed and want to continue using it but can't because of this issue.
I have tried way too many fixes to list here except for reinstall or reset to manufacturer settings.
Any ideas/help?
Thanks

[Nighthawk]

Sounds like an issue with the phone itself if it works fine in another model. The SGH-i727 is 4 years old now so it could be any number of things.

[xray · Accepted solution]

Rooted phones could have any number of reception problems due to installing different kernel and radio firmware.

If you are adventurous you may want to try installing Lollipop.

http://www.android.gs/update-att-samsung-galaxy-s2-skyrocket-sgh-i727-to-android-5-1-1-lollipop-with...

[eng-hossain]

i hope this help you : 10 ways Fix not registered on network error for Samsung galaxy http://mywikispace.com/not-registered-on-network/