SM-G975F/DS stock firmware (android 12) shows "IMEI Status: NG"

[jerseypete]

Wondering if anyone has dealt with this issue. I've got a G975F/DS running stock firmware G975FXXUGHWC2 and IMEI Status shows NG.
What's the best way to fix this? I've tried flashing multiple CSC's, but all show the same.
When trying to install a custom recovery (bootloader is unlocked), I'm unable to do so with the error being shown as: Only signed binaries are allowed.

 

[mustang7757]

Welcome to AC!

Where did you purchase this device?
If you go to settings>about phone>status info>phone status says official?

 

[jerseypete]

I got the phone off of ebay...
Phone Status says Custom.

 

[mustang7757]

Sounds like something was modified , did you get it recently ?

 

[jerseypete]

Sounds like something was modified , did you get it recently ?

I got it in April.
I ended up putting /e/OS on it, but realized when I upgraded to Android 12 that the SIM wouldn't connect to the network. I then started trying to understand what's happening and it appears that the radio is misconfigured, so I decided to flash latest stock firmware for the original CSC.
Everything works (including VoWiFi), except the GSM radio...
I read up on the problem a bit via XDA and it appears erasing /efs may help, but I can't seem to flash a custom recovery to the phone now as it errors out with "Only official binaries can be flashed(RECOVERY)."

 

[mustang7757]

Have you tried TWRP?

You have the international version so bootloader usually unlocked on them , in developer settings you see toggle for OEM unlock ?

 

[jerseypete]

Have you tried TWRP?

You have the international version so bootloader usually unlocked on them , in developer settings you see toggle for OEM unlock ?

Yup, bootloader is unlocked and I tried TWRP with:

$ heimdall flash --RECOVERY twrp-3.4.0-2-beyond2lte.img --no-reboot
Heimdall v1.4.2                                                                              
                                                                                             
Copyright (c) 2010-2017 Benjamin Dobell, Glass Echidna
http://www.glassechidna.com.au/                                                                                                                                                                                                                                                                                                                                                         This software is provided free of charge. Copying and redistribution is
encouraged.                                                                                  
                                                                                             
If you appreciate this software and you would like to support future                    
development please consider donating:                                                        
http://www.glassechidna.com.au/donate/
                                             
Initialising connection...
Detecting device...
Claiming interface...
Setting up interface...
                                             
Initialising protocol...
Protocol initialisation successful.
                                             
Beginning session...
                                             
Some devices may take up to 2 minutes to respond.
Please be patient!
                                             
Session begun.
                                             
Downloading device's PIT file...
PIT file download successful.
                                             
Uploading RECOVERY
100%        
RECOVERY upload successful
                                             
Ending session...
ERROR: Failed to receive session end confirmation!
Releasing device interface...

EDIT: This ended up working after letting the phone sit there and re-acquire the network **AND** rerunning heimdall with `sudo`:

$ sudo heimdall flash --RECOVERY twrp-3.6.2_9-2-beyond2lte.img --no-reboot
Heimdall v1.4.2

Copyright (c) 2010-2017 Benjamin Dobell, Glass Echidna
http://www.glassechidna.com.au/

This software is provided free of charge. Copying and redistribution is
encouraged.

If you appreciate this software and you would like to support future
development please consider donating:
http://www.glassechidna.com.au/donate/

Initialising connection...
Detecting device...
Claiming interface...
Setting up interface...

Initialising protocol...
Protocol initialisation successful.

Beginning session...

Some devices may take up to 2 minutes to respond.
Please be patient!

Session begun.

Downloading device's PIT file...
PIT file download successful.

Uploading RECOVERY
100%
RECOVERY upload successful

Ending session...
Releasing device interface...

 

[mustang7757]

Hmm I haven't used custom recovery in long time on Samsung, might have to reach out back to XDA Forum, so flashing back to stock firmware gives you issues?

 

[jerseypete]

Hmm I haven't used custom recovery in long time on Samsung, might have to reach out back to XDA Forum, so flashing back to stock firmware gives you issues?

Indeed, yes...

 

[jerseypete]

Welp, I guess I need to learn patience.
After having reflashed it with the stock firmware for the CSC, it now appears to have "fixed itself." and joined the network.
I appreciate your replies -- thanks...

 

[mustang7757]

Welp, I guess I need to learn patience.
After having reflashed it with the stock firmware for the CSC, it now appears to have "fixed itself." and joined the network.
I appreciate your replies -- thanks...

Anytime glad its working