Instructions
Hold the "PS" button on your PlayStation 3 controller. Whether you are viewing the console's main menu or playing a game, this will cause the same menu of options to appear on screen.
Select the "Turn off Console" option to place your PlayStation 3 in "Standby" mode.
Flip the "Power" switch on the rear of your console. This will completely shut the unit off. Wait a few minutes before powering the console back up to allow its internal components to cool down. Typically 5 minutes is more than enough time to allow the system to cool.
Flip the "Power" switch on the rear of the console back into the "ON" position. This will place the PS3 back in "Standby" mode.
Press the "PS" button on the controller to turn the console back on, finishing the reboot process.