I have an unlocked S7 Edge from sprint, a cdma carrier. Im with metro now, a gsm carrier, and would like to reuse this phone if possible. In network settings there are a few settings, LTE/UMTS, GSM/WDCMA, and Auto Connect. On LTE/CDMA i get data aswell as texting but cannot call or sent/recieve mms. On GSM/UMTS I can call others and have data but at gsm speed (which is ridiculously slow). Id like the best of both worlds and to force LTE/GSM by dong this in the service mode settings, accessed by dialing *#0011#, but i ran into a problem. Others online simply go to servicemode, go BACK, then input key "Q", go BACK, then Input Key "0000" and it opens the network band settigs. However mine doesnt and once it displayed the following message "MENU NOT EXIST PRESS BACK KEY Current Command is 110"