This message is addressed to anyone that may be unsure about what freaking modem they should flash or how to flash.


First of all... Go here (just click, it's hyperlinked). Input your phone model and country + carrier. Then press "Check firmware" and observe the result. You're not gonna have to care much about the PDA and CSC, just the MODEM.
Note: When a carrier pushes a new update OTA, they update both GSM and LTE modems.

In my case, the latest modem my carrier seems to have pushed OTA is XXUFNB8, which I am going to stick to for a while. And I'm not gonna waste my time / nerves with flashing a new modem every couple of days, some times ending up with issues that I never had before.
Note: I am talking strictly about GSM (2G/3G) modems now.

If the modem your isolated carrier / country last pushed OTA is nowhere to be found... bad luck Brian. Flash a modem that has a naming scheme similar to the one your carrier has (or used to have?).

Now. LTE (4G). Do you need it?

New bootloader (KNOX sh*t) => you need to flash LTE modems that are newer than XXUBMH1 (like, for example, a very recent LTE modem such as XXUFNB9). Otherwise, sound / Wi-Fi may break.
Old bootloader (no KNOX ) => you need to flash exactly the following LTE modem and no other : XXUBMH1. Otherwise, sound / Wi-Fi may break.

But... What the hell is a modem?!

A modem is usually a file with the .tar or .tar.md5 extension. If you look inside the .tar archive, you will see the actual modem file(s).
modem.bin = GSM (2G/3G) modem; NON-HLOS.bin = LTE (4G) modem.

A LTE (4G) modem is often refered to as Wi-Fi fix. Why? Example : you have the old bootloader and flashed a wrong LTE modem (a new one), so your Wi-Fi (and/or sound) is now broken. Flashing XXUBMH1 will fix Wi-Fi (and/or sound), so XXUBMH1 is a Wi-Fi fix (for the old / non-KNOX bootloader).

You can flash any GSM modem you want, regardless of the bootloader. The only tricky part is when it comes to LTE, as explained above.

Oh, and one more thing. If you're thinking of asking what modem you should use on carrier X in country Y... first of all, make sure you did what you've read on the 2nd paragraph of this post. If you can't find any relevant info (which would mean you live in some isolated place), then ask...

How to (properly) flash a modem?

1. If you're using a custom ROM which has some sort of advanced power menu where you can select Reboot -> Download Mode... choose Power Off instead.
2. Now, press & hold the power, volume down and home button. When you're greeting with an informational screen, press volume up.
3. Connect the USB cable (not to a microwave oven).
4. Start Odin (preferably version 3.04 or 3.07). Make sure all checkboxes on the left hand side of the screen are NOT checked.
5. Select "PHONE" and link to the modem file you want to flash (modem.bin, modem.tar, modem.tar.md5).
6. Once the process is done (wait for the green box to turn green and display PASS), disconnect the USB cable and hold down the power button to reboot the phone.

Flashing a modem in Odin will not wipe your phone, provided you do it correctly (as stated above) and don't do anything else stupid.


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I'm gonna bookmark this post and every time a newbie comes over with a serie of questions, I'm gonna link him to this post. Which is what I'll be doing every 2-3 pages, I reckon. If you could do the same, that'd be great.