Side BUTTON Not working to Lock the Phone M51

[RitzPune]

My side power Button is not locking the phone 

[Vicky_A52]

Pls check it in samsung store nearby service center

[RitzPune]

This Buttons works sometimes and does not work sometimes

[ᗰOᕼᗩᗰᗰEᗪKᕼᗩTᖇI]

Did water go Inside that?

[RitzPune]

No

[Kawsar4s]

go to power button setting in your phone, Then turn off or on

[ŞàyáņĐàn]

You may enable "smart lock"...
Check this in settings

[rufus1804]

Maybe the switch got damaged after frequent usage... try to turn on the option for double tap to wake feature it will help to reduce the usage of side key ,thus protecting it

[cs-member13]

Dear Samsung Member,

Greetings from Samsung Customer Support!

We would request you to register your concern in Samsung Members Application. So, that our concern team gets back to you as soon as possible.

Please follow this path to register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).

Note. please attach the error log file within 15 minutes of the error occurred.

Thank you for writing to Samsung.

Warm Regards,
Samsung Customer Support