I don't know exactly whats the problem other than what you have stated wifi is not work and I don't know what have you done so far to fix the problem. however, if you can hard wire your box with ethernet cable then check for update and try to download latest version.
in order to download update go to setting
click update
type 0227 on your remote control
press red button and download
if nothing works then I would recomend you to save all donation/code info and if you know how to setup again then try to factory reset your box and see if that helps.
Unplug STB for 30 sec.
Plug in and check Settings /Network /Wifi (Enable it and see if the STB see's your Network (or other networks)
*When all else fails, ... Hard Reboot.