[Q] Pantech Vega No.6 can't connect to WIFI topic

hello there. hope you can help me. i'm using a SKY VEGA NO.6 and it's kinda picky on WIFI connections. i got a new modem and still doesn't work. i've tried remorfatting my phone. it work for a bit and it's back to it's problem. is there a tool that i can use? thanks in advance. :(