This forum is for information related with F series hardware.
How that mainboards looks? Are they same or there is some diference? It could be possible that for upgrade it is needed also change other components maybe T-con or PowerBoard or simply setup correct values in Service menu. I'm interesting with this things.
UE48H6640 T-MST14DEUC 2781.0 root latestH --> 2130.0 skypeRoot-->0000-->2115.3 "Skype refueled" Root