several days ago I was leastning to music and my phone turned off. It didn’t turn on. I tried to connect it to pc but pc didn’t see it. I charged it about 2 hours and then it turned on by power button. But now it only works with 2G network. When I switch to 4G data transmission doesn’t work. When I switch to 3G sometimes I can call but usually calls are interapted. Firmware was 4.5.7i. After the issue I’ve tried to ROM with all wipes to 126.96.36.199A and downgrade to 188.8.131.52I. Situation was the same. I’ve tried another SIM card but it has not helped. Help me!