Can you tell us if the MFG menu works? Info:
Dial ##634# to open the diagnostics menu.
Open the MFG app using the password: appmfg#*#
Go to Engineer Menu -> Other Settings -> Edit Registry
Set ROOT PATH to "HKEY_LOCAL_MACHINE"
Set input path to "\Comm\Security\LVMod"
Set input key to "DeveloperUnlockState" and it set to DWORD.
Leave input data box empty and tap "SET".
The output should be 0.
Enter "1" in the inputbox and tap "SET".