Secret Codes and Hidden Menus

Any secret codes or procedures to access hidden menus on mobile devices will be listed here.

'''Note that some of these menus may give access to variables that are critical for certain phone functions. Do not change any value unless you are absolutely certain about what it's used for!'''

CDM-4000, 9000, 9100, 9155, 9500 (Toshiba)
'''Service menu is used for NAM programming. Proceed with caution!'''

To enter the service menu, first power on the phone and wait for the status light to turn off. Then type the following code in order:

289 F (right arrow key)
 * 1

To enter the test menu, first power on the phone and wait for the status light to turn off. Then type the following code in order:

F (right arrow key) 00 000000 (FSC code; should be all zeroes by default) F

All LG GSM phones
On LG GSM feature phones, the service menu can almost always be accessed by entering one of the following codes:

2945#*# For older LG GSM feature phones

Or, where {model} is substituted by the number corresponding to the phone's model (for example, 460 for an LG B460):

1809#*{model}# For newer LG GSM feature phones

If neither of these work for you, try: 3845#*{model}# 277634#*#

GSM phones
On many Samsung GSM models (both GT and SGH), there is a test mode that can be accessed with the following code:

For the majority of Samsung GSM feature phones and some smartphones
 * 0*#