On Nokia 1110 — How To Use Secret Codes

This compresses the voice signal further. It results in lower audio quality but extends battery life by roughly 30%. To deactivate, use #4720# . Tips for Success

Some retail Nokia 1110 units have a demo mode loop. How to Use Secret Codes on NOKIA 1110

to reset phone settings without deleting your personal data like contacts or messages. Hard Factory Reset This compresses the voice signal further