wanna share another refference for ZH&K androin no hand reset only factory set..
use 5310 cable
i used 3.20a version
connect box
then back up first
uncheck SCAN PIN OUT tab
6820 android setting
tick readflash
turn off your phone
then press and hold up and down volume
then insert cable
release if detected

after finish back up
formating just same procedure in connecting
and check only FORMAT USER DATA option

done fast format