Apple iphone5s/5c Phone lock screen no sound How to solve (IOS7)

iOS7 version of the iphone

1. On the phone's "settings"

2. Then we go to the "sound" option.

3. Then find the "lock sound"

4. Then click on the "Lock sound" off, and then open

5. If there is still no sound we press one by one "power lock button" does not move until there is a sliding shutdown screen, and then slide off the machine, as shown in the picture

6. After the boot, we look at the "Power Lock key" reboot, and finally try to lock the screen to confirm whether there is sound.

If the above methods have tried or not can be your mobile phone has a problem, we have to rework oh.