"Unknown is an indication of a »lost baseband firmware«.
The device manufacturer with the mobile provider is responsible for the baseband firmware and is located in the Samsung StockROM. This firmware can be flashed with the Samsung ODIN3 Tool.
An example from the 4-part StockROM of Samsung Galaxy S7 SM-G930F (MODEM/CP version) :
CP_G930FXXU2DRB6_CL648265_QB8952207_SIGNED.tar.md5
No customROM contains this software - probably for copyright/license reasons.
Alright, so at what point do I add that in the install of /e/, and do I need to add one from the same version (IE 7.0) of Android?
1/ … after flashing /e/ OS
2/ … it is recommended to first install a baseband-firmware from a StockROM 7.0. In your special case I would additionally flash the bootloader-firmware (because of “reboot…”).
(Tip: Keep Posting #19 in mind).
First download a multi-part, usually 4-part (“Binary Nature”), StockROM 7.0 for the SM-A520F. Extract the compressed *.zip file. The result for the SM-G930F mentioned under #21 looks like this:
AP_G930FXXS2DRDI_CL12365438_QB17789072_REV00_user_low_ship_meta.tar.md5
BL_G930FXXS2DRDI_CL12365438_QB17789072_REV00_user_low_ship.tar.md5
CP_G930FXXU2DRB6_CL648265_QB8952207_SIGNED.tar.md5
CSC_DBT_G930FDBT2DRB5_CL13061583_QB16917211_REV00_user_low_ship.tar.md5
Now in ODIN3, fill the fields “BL” and “CP” with the corresponding file from the 4-part-firmware and enter “START”. The SIM card can then be inserted.
After the installation procedure a reset to factory settings is necessary depending on the device.
Downloading a new copy of the 7.0 firmware now. The first 7.0 I downloaded was part of what didn’t initially work on Odin - the BL and AP files caused errors in Odin. I’m downloading the general Canada version of the firmware (XAC) which is the version that installed successfully for 8.0. Download is just going mega-slowly at the moment.
So correct order here…
Now… if ALL that fails again, what I’m wondering is where are these files stored with the OS? It may be possible to backup those directories and their contents from a working Android 7.0 and then copy them back up (via adb) to the phone once it is running /e/. It is, after all, still a Linux install under the hood.
Hej, I’m not sure if I understand it right:
You’re downloading StockROM 8.0 (Canada XAC) now and want to combine the BL & CP it contains with /e/ for a5y17lte dev (nougat)?
Sorry for the lack of clarity there. I already had the StockROM 8.0 downloaded - it was what I installed a few days back to confirm that the SIM did work with the “stock” phone setup.
I’m downloading the StockROM 7.0 right now - Canada (XAC) version - so that I have a CP and BL image that match the base OS version of /e/.
Yes, I believe that this is the right way to go at the current stage of troubleshooting.
Didn’t work - just like the other carrier specific StockROM 7.0, it errored on trying to push up the BL:
@Dakiraun, I can’t find firmware (Canada - XAC) for the Samsung Galaxy A5 (2017) SM-A520F SM-A520F “a5y17lte”. Please give me a link to the download page you used.
It’s the SM-A520W that I have. This is the firmware I tried:
https://www.sammobile.com/samsung/galaxy-a5/firmware/SM-A520W/XAC/download/A520WVLS2BRD2/217443/
I just booted the phone up after the /e/ install. First, I was able to put on the StockROM 8.0 BL, but used the 7.0 CP file. SIM card is still not detected, and baseband shows as “Unknown”. Seems to not be seeing/using those firmware files.
SM-A520W is not compatible with /e/ OS (or LineageOS).
Only the European Vesion of Galaxy A5 2017 SM-A520F is supported. We should have recognized this earlier … ;o/
facepalm
Argh. As I’m beginning to discover with these phones, there are SO many versions and sub-versions of the “same” phone that it’s dizzying. This is why I avoided having one of the stupid things until now.
Alright, so magic question - when is /e/ going to be ported to the Canadian and US versions of these phones?
I can’t answer that question for you. First contact person should be @Manoj /e/ support.
Alright, will do. Thank you for all your patience and help - certainly have learned a lot about phones in a short time. 
Me too. See you next time.
Supplement:
The Samsung Galaxy A5 (2017) has more variants. Only the versions (SM-A520F) and SM-A520F/DS (Dual-Sim) are supported by /e/ OS (and LineageOS).
MOD 1**
Samsung Galaxy A5 2017 SM-A520F Single-Sim
Specifications Samsung Galaxy A5 (2017)
Countries or regions available: Europe.
MOD 2
Samsung Galaxy A5 2017 SM-A520F/D (Global Dual-SIM)
Countries or regions available: Latin America, Saudi Arabia, Brazil, United Arab Emirates, Philippines, Malaysia, Russia, Singapore, Thailand, Ukraine, Various (International).
MOD 3
Samsung Galaxy A5 2017 SM-A520K / L / S
Countries or regions available: South Korea.
MOD 4
Samsung Galaxy A5 2017 SM-A520W
Countries or regions available: Canada
