Sleep key shortcut for Inspiron 5402 i5

Welcome to the Dell Community @Rahul N 

1. Press Windows key + X, followed by U, then S to sleep

2. Set the option for the Power Button to put the laptop to sleep.

OR

1. Right click the Desktop and select New - Shortcut.
2. In the shortcut target box, type or copy-paste the following command: c:\apps\sleep.cmd. Correct the file path according to your preferences.
3. Set the desired icon and name for your shortcut.

Best regards,

U2

You can try Fn+F4 and Fn+F1.

thanks but its not working , I tried it. 

Window+x  U S  is working fine.

Thanks you so much.

Option 1 and 2 is working fine for sleep shortcut .

Could you please share  corrdect command for path - [command: c:\apps\sleep.cmd. ] ?