RCA tablet Authentication issue to connecting to Wifi

I have an with my 7 inch RCA Tablet I've owned for 2 years or so. The Mdl #RCT6378w2. I tried connecting with Password or PIN and it still wouldn't not connect me this time. I talked to RCA and they said since my warranty ran out, I need to send it them for repair $30 but I want to try this first since i paid for the tablet about the same price to get it repaired. Please help me to get this going. I used this all the time.