You have spilled liquid (water, coffee, etc.) on the Walkman.
You have washed the Walkman in a washing machine.
Contact the nearest Sony dealer or Sony Service Center.
Liquid may get inside the Walkman in the situations listed above.
Stop using the Walkman immediately. Then, contact the nearest Sony dealer or Sony Service Center.
The contents of the Help Guide may be subject to change without notice due to updates to the product's specifications.