Hi, im from peru, recently bought a cell phone model: Samsung S4 I9505 Factory Unlocked (AP:i9505xxuemk8 Modem: i9505xxuamdc CSC: i9505btuemk5) Android 4.3; the phone recognizes my network operator (movistar) without problems but when the phone goes into "deep sleep" mode and i turn on, it loses signal (check images) and the signal returns after a few seconds (or minuts), only GSM Netwotk Mode works fine, please be patient with me, because i'm newbie, thank you.
All is ok less the modem. You will have to download and extract this
MODEM. How?
1. Download ODIN and start it as administrator.
2. Now open the windows taskmaster. End all "Kies" processes.
3. In Odin untick "Auto reboot"
4. For the bootloader select BL and browse to your bootloader file.
5. For the modem select CP/PHONE and browse to your modem file.
The next step is VERY IMPORTANT
6. Power off your phone
7. Start your phone into download mode by holding Home button + Vol down + Power button. Volume Up then (PIC 1)
8. Once your phone is in download mode, connect it to your PC. (Best results always with your original Samsung USB cable)
-Odin should say "Added" now.
9. Press the Start button in Odin and let it do it's magic. Wait. (PIC 2)
10. When Odin shows "PASS" you can unplug your phone.
IMPORTANT: WAIT UNTIL YOU SEE "PASS" DO NOT UNPLUG THE PHONE BEFORE!
11. When you have unplugged your phone, it is still in download mode. Just hold the power button about 8 seconds until your phone reboots.
DONE
Go to Settings/More/About device. There you will see your new baseband.
12. Do this process one time more if u still seeing the old modem/baseband.