hi
i have problem wid my cid 53 phones. the prb is i finish unlock my two phones one is k530 db2020 n second is w380i pnx5230 successfully but next day customer bring the phones again to me, now the phone is dead after that i download the flash files for these phone n flashed it. its working again fine but next day same thing its go off again

plz help me why its gonig off by self ?????????