If like me you’ve been tampering with your device a fair bit, chances are you’ll need to use some of these. I found the following so far. Use these at your own risk.

– Access the GPS menu: *#*#3214789650#*#* then go to SUPL / CP Settings and select FQDN Type / AUTO Config.

– EMEI: *#06#

– Change the sales product code (beware, this will format your phone and remove all apps/data): *#272*YOUR IMEI#

– Reformat the phone (remove your external SD first): *2767*3855#