Life line call.... Note 3 Lollipop issues and downgrading. Now no mobile connectivity

[BCL_WA]

Problem- Had a 4.4.2 Note 3 which ran fairly well. Decided to upgrade to Lollipop and for the most part it was ok with the exception of not being able to set a pin for security. Everything worked including low battery usage. Subsequent factory resets never resolve this issue with setting a PIN. I resorted to Kies and re-flashed using Samsung's latest/greatest Lollipop (again). It corrected the PIN issue + restored root but introduced a new problem with no mobile connectivity to the Tmobile network. Attempts to manually define the APN, mobile network selection have not worked. Factory resets no good. Nothing!

Attempted Resolution - I rooted lollipop and then downgraded back to a stock ROM build (which is rooted as well) 4.4.2 .
Here's my issues. I still cannot connect to the Tmobile network. Everything else is fine but no mobile network connection. Again attempts to manually define the APN, mobile network selection have not worked. The SIM is good as it works in other devices just fine.
I fear I corrupted the IMEI As I get a IMEI Certi: FAIL, -4 when doing *#0011#*
However, the proper IMEI is listed in the Settings- STATUS section. This isn't a blacked listed phone either.

I am in the process of downloading "NF9[[odin]][[tar]]stock 4.4.2 tmobile NOTE 3 ONLY" from xda forums.

...based on research done. I intend to flash it again. I think the modem is hosed.

If anyone has any wisdom out there regarding this problem, please speak up.
If I'm on the wrong path let me know.

Appreciate the help in advance.
-B

 

[Rukbat]

introduced a new problem with no mobile connectivity to the Tmobile network. Attempts to manually define the APN, mobile network selection have not worked. Factory resets no good. Nothing!

Just so you know, the APN is to connect to the internet, not to the carrier's network. You have to connect to the network to connect to the internet, but you can connect to the network with ab incorrect APN.

Attempted Resolution - I rooted lollipop and then downgraded back to a stock ROM build (which is rooted as well) 4.4.2 .

Rooting Lollipop was a waste of time, then. You root the ROM, then replace it, so su - the only file that makes any difference - is lost unless the new ROM has it (which, in your case, it does).

Here's my issues. I still cannot connect to the Tmobile network. Everything else is fine but no mobile network connection. Again attempts to manually define the APN, mobile network selection have not worked. The SIM is good as it works in other devices just fine.
I fear I corrupted the IMEI As I get a IMEI Certi: FAIL, -4 when doing *#0011#*

Sounds like it.

...based on research done. I intend to flash it again. I think the modem is hosed.

That could be. The 5.0 update hosed my AT&T Note 3 modem. I kept calling tech support until I got a supervisor who agreed with me that since it was their forced update (you don't get a choice - eventually you have to take the update) that broke the phone, it wasn't a warranty issue, it was a liability (theirs) issue, and he sent me a new phone.

Flash a stock (not rooted) current Lollipop (whatever TMobile is up to for the Note 3). Then if it still doesn't work, try your local store. If they won't help, start calling tech support and speaking to supervisors.

 

[BCL_WA]

Rukbat, thanks for the quick response. I ended up flashing with the last ROM I mentioned and still no go with network connection. I have verified the IMEI *#06# is accurate for the phone. Really at a loss on this one. I understand upgrading ROM can help rebuild the IMEI so I may try the dreaded lollipop once more. But before I do this I'm going to visit the local store and see what I can do. I highly doubt I can be lucky as you with getting a replacement as I bought this used over a year ago + rooted it and applied Lollipop via Kies myself (no auto download).

I can make calls over wifi and in fact Tmobile just sent me a 17mb update via a wifi connection of course- go figure. It no longer has root obviously. I guess I may have a new TV/Media remote now.

-B