i found a simple solution for all samsung s4 devices which due to downgrade or upgrade lost its imei baseband and signals it work on my s4 GT i9500 i update it on lolipop 5.0.1 but when trying to sale it he say i need 4.4.4 in this device i contact many software installer persons to do it but they say it cant be possible your device might be dead in this process of if done it was costly some how i do it by myself coz i know the tricks use odin 3 for this purpose found the firmware from www.sammobile.com get registered first and a fast net and pc coz file has 1.5gb size after all this process i lost signals no imei and baseband firmware 4.4.4 then i search and found this file called modem.bin for s4 i flash and now it has its imei, baseband and signals of Pakistani network zong part o china mob corp my problem is fixed now try it it will cost a lot when u try it from samsung or market so try it yourself easy process just flash phone file select this bin and flash it in download mode i hope it fixed
