I bought my wife a NOkia 1650. Now this phone randomly resets, and she has to enter the pin-code again. The phone does not restart.
Last time she was playing snake, and when she lost, the phone vibrated, and displyed the message: "enter pin-code" again. It may have something to do with the vibration I think, but it's no option to switch this off.
Anyone knows what this could be
Remove the battery and look where the Sim card is inserted.
If the gate that holds the Sim card is not locked into place then the Sim might come loose.
If at any point, when the phone is on, the Sim card cant be read by the phone it will reset the phone.
I have nearly the same problem. My phone wants the PIN code once a day. Always at the same time (about 7pm20)!!
Checked the simcard-holder but everything seems ok. Will see if the problems persists after having removed the accu and checked the holder.