Remove the battery for about a minute.. Insert and switch the phone ON.. Now check.. Else you may have to do a Soft Reset by dialing *#7370# followed by the security code 12345(Default) when prompted.. If you have set your own code.. use that instead..
Be warned that this will erase all data from the phone memory.. so take back-up before doing...
hello! i had the system error problem in my nokia c6 so i tried the *#7370# method.now the system error problem is gone but neither my music player works nor my photos.moreover the battery gets too hot.i use 8gb micro sd card.pls help!