Check the warranty status of your phone.
Enter *#0000# on your phone’s keypad. The display shows your phone’s model and product code.
On older phones, these numbers are printed on a white label in the battery compartment, underneath the battery.
No. You can only change font size for messages in your device. To do so, select Menu > Messages (or Messaging) > Message settings (or More > Message settings) > Font size (or General settings > Font size).