Upgrade firmware B1-A71 from China
I bought B1-A71 in China. The tablet's firmware is Acer_AV051_B1-A71_RV04RC05_GC_GEN1 with all Google service disabled.
I donīt want to root it. I only need to upgrade to Acer_AV051_B1-A71_RV05RC05_WW_GEN1
There is no upgrade option in settings. I tried to manually update it but always got this error:
assert failed: getprop("ro.product.name") == "B1-A71_ww_gen1"
Any idea to upgrade these tablet?