Four keys not working prevents entering password for WIFI

Attn G-Beards or anyone: Purchased tablet in 2014, but only used this past 2 weeks. Have done manual reset. Have read through 2 hours of info from you guys, but haven't found what I need yet. All keys worked fine for the 2 weeks. 2 letters (r and c) and corresponding 4 and * just stopped entering. I have 2 WIFI accesses and of course #4 and c are needed for passwords. Any suggestions greatly appreciated.