[Galaxy S 4 General] sleepingscorpion:
Device: i9505 / Qualcomm Snapdragon, locked to T-Mobile UK, went striaght from Samsung Stock ROM to CM11 on purchase in 2013.

Computing Platform: Macbook Pro - OSX Yosemite

Flash tool of choice: Heimdall 1.4.0 - cmd line !!! :)

Context:

I updated from CM11 to CM12 - no issues. I decided to update to the Radio/Modem to the latest for Lollipop.

Went to the relevant thread, downloaded 'I9505XXUHOB8_MODEM_and_I9505_XXUHOB8_WiFi_FIX' which included the modem.bin and the non-hlos.bin files.

Flashed via Heimdall on the cmd line, all went ok.

Booted the phone, wifi ok, cell data transfer ok, BUT no sound (touch sounds ok, no ring tone, or ringer adjustment tones), phone app unresponsive - very laggy, forced reboot, no sound on calls :(

Tried other touted solution of mixing and matching various versions of modem and non-hlos - no luck.

Aim: Fix issue without having to ReFlash stock ROM - after all its only two files that caused an issue, just needed to know why?

After a lot of googling and searching xda, I got nowhere, only option seemed to be flash stock FW.

Started reading a lot around the modem.bin and non-hlos.bin - seemed not much info about at high level for the non-hlos.bin; began reading in depth about flashing and boot-loaders.

Solution:

the modem.bin and non-hlos-bin that are flashed need an associated (or close) version of the bootloader of the same!

I downloaded the BL_I9505XXUHOB8_user_low_ship_MULTI_CERT (also tested with BL_I9505XXUHOB7_user_low_ship_MULTI_CERT which worked fine with the above XXUHOB8 modem and non-hlos!)

Untarred all into a single folder/directory ie XXUHOB8 :

-rwx------@ 1 myusername staff 12147712 26 Feb 09:23 NON-HLOS.bin ----> XXUHOB8 MODEM binary

-rwx------@ 1 myusername staff 52304896 26 Feb 09:23 modem.bin ----> XXUHOB8 NON-HLOS binary

-rwx------@ 1 myusername staff 1313312 25 Feb 16:45 aboot.mbn ----> XXUHOB8 Bootloader Files

-rwx------@ 1 myusername staff 153696 25 Feb 16:45 rpm.mbn ----> XXUHOB8 Bootloader Files

-rwx------@ 1 myusername staff 94772 25 Feb 16:44 sbl1.mbn ----> XXUHOB8 Bootloader Files

-rwx------@ 1 myusername staff 152168 25 Feb 16:44 sbl2.mbn ----> XXUHOB8 Bootloader Files

-rwx------@ 1 myusername staff 270664 25 Feb 16:45 sbl3.mbn ----> XXUHOB8 Bootloader Files

-rwx------@ 1 myusername staff 217068 25 Feb 16:45 tz.mbn ----> XXUHOB8 Bootloader Files

I inspected the .PIT file, determined the order (may not be necessary, but I was unclear, so...),

put phone into download mode (from complete power off, Volume Up & Home & Power button, then release power button and press Volume Up to proceed)

and then ran the following:

heimdall flash --APNHLOS NON-HLOS.bin --MDM modem.bin --SBL1 sbl1.mbn --SBL2 sbl2.mbn --SBL3 sbl3.mbn --ABOOT aboot.mbn --RPM rpm.mbn --TZ tz.mbn --verbose --no-reboot

Turned the phone off by holding the power button.

Then back into download mode

Next I reflashed CF-Auto-Root using heimdall - again untarred to a folder:

-rw-r--r--@ 1 myusername staff 9199616 7 Aug 2014 recovery.img ----> CF-Auto-Root Recovery Image

-rw-r--r--@ 1 myusername staff 17330396 7 Aug 2014 cache.img.ext4 ----> CF-Auto-Root Cache File

then flashed using the following:

heimdall flash --RECOVERY recovery.img --CACHE cache.img.ext4 --verbose --no-reboot

turned phone off, holding power button.

Then booted into Recovery (Volume Up & Power)

CF-Auto-Root took over and did its thing.

At this stage I had lost custom recovery to Samsung Stock Recovery, so to get it back, again using Heimdall...

unaterred CWM Touch into a folder:

-rwxr-xr-x@ 1 myusername staff 8878080 29 Feb 2008 recovery.img ----> CWM Image file

Powered off completely.

Back into Download mode

then flashed as per:

heimdall flash --RECOVERY recovery.img --verbose --no-reboot

Turned off completely using power button.

Then booted into recovery to check that CWM was back, and it was.

Whilst in CWM, wiped the cache and Dalvik, refalshed my CM12 nightly, and rebooted.

ALL FIXED! and all without having to reflash stock!

HTH

Peace to all.