Wifi works but "not in range"

My Note II (actually now my daughter's Note II) has developed an issue with the wifi where it will turn on, but everything is out of range, even if I put the phone, wihtout its case, next to our router. The local repair shop have charged £20 and acheived nothing apart from the wifi and Bluetooth will switch on, rpevioulsy they had the "greyed out" issue.Apparently there is a"possible board failure". All suggestions involving fixing it at sensible cost are very welcome. Daughter loves the phone and is eyeing my Note 4 with acquisitive eyes!