Backdoor

In Blackberry, there are documented "backdoors" (ALT + 4 letter combinations) and undocumented backdoors. There is an API to implement backdoor. Some key combinations are documented, but some are not. Some of these backdoor have immediate and visible effect (like typing ALT-ESCR in home screen), but some combination does something that is not visible. I will try to list some of the backdoors that I found, especially the ones that is not publicy known.

I will write: "invisible action" when you will not see anything, but something happens in background.

Main/Home Screen

Need to hold ALT in this screen

DCLR : Clear cache hash table (invisible action)
DPAP, ESCR, EACE: help/engineering screen
DUMP: Dump hash table content to debugging port (need to connect to JDE to see the result of this)
JKVV: Show reject cause
LGLG: Show log viewer
LONS: invisible action, HomeScreenInternal.toggleLogONS( ) // calls this (not sure what it does yet)
NMLL: toggle view signal strength in dbm or bar
ONSA, ONSB, ONSU: invisible action change ONS rendering mode (by presence of SIMServiceTable.B_SERVICE_PROVIDER_DISPLAY_INFO ,by SIM is not compliant to TS11.11)
QSMD: Set send report mode
QSMI: ?
SQRD, SQRP: Send report ( net.rim.device.apps.internal.api.quincy.QuincyManager)

Options

In some screen (like in the OptionsScreen), you don't need to hold ALT when typing

in Application Options, COMP will set compatibility options to default (it will not show anything on screen)
in Auto On off Options, typing AUTO will show the next date/time auto/on off will be performed
in Date/Time Options: ADST (enable auto adjust clock for Daylight Saving Time), DELT (Time Zones Delta Count), LOLO (Manually adjust network Time Zone offset and DST)
For device with touch screen: in keyboard options VKBB should show something (I haven't tried, and right now I am not in the mood to trace the code)
In Location Options, AGPS will show AGPS setting
Network Options, OMDM will show sync settings if Escreen access is enabled
Security Options, CTDG will set AuthCert Status Period (it will not show anything on the screen)
Status Options, BUYR (show status), FTOT (), TEST (run self test/execute net_rim_bb_device_selftest)
Sms options: SMSP (SMS Service center)

Help Screen

Only one backdoor sequence: ALT - OPEN open help file

App world

Appworld backdoor keys are only 3 characters long

ALT - BIS: Toggle force BIS_B
ALT - RST: reset keyed store
ALT - UOI: user interface test (only shows a useless screen)
ALT - LOG: Show log

Links: modules