For quite some time of trying out various roms on my I9500, I've found out that on all of them I had a call issue, where the other person kept hearing himself twice (echo). I've tried today to flash a modem for it, but for some reason, now it doesn't identify the sim card anymore.
I've tried flashing other roms, including wiping of everything except for internal&external storage, of course.
The sim card itself is fine, as I can see it working well on Nexus 5.
What can I do to fix this?
ok, I flashed an old modem, and it worked: http://forum.xda-developers.com/showpost.php?p=58658207&postcount=2729
Sadly, the calls still have issues, but at least the sim card identification is ok.
If anyone knows how to fix this, please help