On my n79 the camera automatically turns on and off randomly and even the keylock get unlocked automatically and randomly every second,the phone get hanged up as the mobile screen turns even when the turning control is set to off.i cannot make a call..it makes impossible to type a msg.i have tried hard reset,soft reset ,memory card format,nothing has worked i am unable to find a solution.please give a solution asap.

Mostly all nokia phones have a full phone lock along with a keylock.
To enter a security lock, you need to activate it first.
for this,
go to your settings-> phone settings and scroll down to security keyguard. Then switch it on in case it is off.
Note: in case your phone locks at this moment, the default keylock is 12345 to unlock
After this you need to put in a new password to the security keylock
For this, Go to Settings-->Access codes--> Change Security code
Enter the default keylock i.e. 12345 . Then enter a new password which you will remember. Verify it by entering it again.
After you have done this, go back to settings->phone->Automatic Keyguard
Switch it on and enter the time for the keylock ( can be 5,10 or 15seconds depending on your choice)
After all this is done, you are good to go. Just remember your passcode.

You can get the Unlock code from the Online Site.....

To unlock the keypad:
Press the * key and select Unlock.

To manually lock the keypad:
Press the * key and select Lock.
To activate automatic keylock:

1. Select Menu > Settings > General (tab).
   
2. Select Security > Automatic keylock > On.
   

According to pg. 45 in the owner's manual, you turn Keylock function ON by holding down the ENTER key on the projector for about 5 seconds while the projector is being turned on.

To take the Keylock off-- Hold down the ENTER key on the projector for about 5 seconds. If the projector is in standby mode, you can release the keylock by holding down ENTER and STANDBY/ON keys simultaneously for about 5 seconds.

go setings

You can manually lock the keypad to avoid pressing keys by accident. You can still answer an incoming call and the keypad will lock again when the call is finished. The keypad remains locked until you unlock it manually.
Depending on your phone model, you can activate the automatic keylock. When the automatic keylock is activated, the keypad locks shortly after you stop pressing keys.
Please note: with some phones you can still use external keys when the keypad is locked. If you wish to lock the external keys you must lock them separately.

K530i To manually lock the keypad:

1. From standby, press the * key.
2. Select 'Lock keys'.

To activate automatic keylock:

1. From standby, select 'Menu' > Settings.
2. In the General (tab), select Security.
3. Select Automatic keylock > On.

To unlock the keypad:

1. From standby, press the * key.
2. Select 'Unlock'.

Hey All
I had the same problem.. did your screen keep changing colour when your N79 virbrated??

WELL... Turn your phone off.. take off the back cover.. and leave for 10 mins. Then put on the back cover and switch on..
Then like magic its behaving it self.. for now!!
Hope this helps
Rich :o)

You can manually lock the keypad to avoid pressing keys by accident. You can still answer an incoming call and the keypad will lock again when the call is finished. The keypad remains locked until you unlock it manually.
Depending on your phone model, you can activate the automatic keylock. When the automatic keylock is activated, the keypad locks shortly after you stop pressing keys.
Please note: with some phones you can still use external keys when the keypad is locked. If you wish to lock the external keys you must lock them separately.

K800i To manually lock the keypad:

1. From standby, press the * key.
2. Select "Lock keys".

To activate automatic keylock:

1. From standby, select "Menu" > Settings.
2. In the General (tab), select Security.
3. Select Automatic keylock > On.

To unlock the keypad:

1. From standby, press the * key.
2. Select "Unlock".
3. hope this helps Thanks and God bless

Press the power on button and then select KeyLock.
Its a stupid way of having to do it though...