i have 831c (htc). I tried unlocking all bands but i stopped at the last moment. After a day the phone had no signal. i tried all things cleaning sim removing rebooting etc. The same sim works fine on other phones. The phone is factory unlocked and used to be locked on sprint. It keeps on asking for activation though after avoiding it goes away. Whenever i put the sim in , in cdma only or lte/cdma mode. It shows no sim. and when i use gsm/utms only it says invalid sim contact customer service. I have shifted to asia. Help
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