06-27-2017, 05:51 PM
I have a vivo y51l (Qualcomm) android phone. I sent it to service center to enable volte and they enabled it and upgraded it higher version of android.
But after this battery is draining very fast and I contacted service center again to downgrade it but they said ____they can't downgrade it to stock rom.
So pls suggest me a safe way to flash stock rom so that I don't lose my imei and nvram etc.