Simple Reset
The simplest reset for your PS3 is turning it off and then back on again. If you're experiencing simple errors or difficulties with the console, often this type of reset will correct them. You can of course select the "Turn Off System" option in the "Users" section of the XMB menu to power down the console, but you can also use the power button, which is helpful if a game has frozen or you're unable to use the PS3 for another reason. Just press and hold the power button on the PS3 for a few seconds until you hear a beep; in a moment the indicator light will turn red to indicate the power is off. You can now turn the console back on by pressing the power button or pressing the PS button on a controller or remote.
Video Output Reset
Sometimes, especially if you get a new TV or use different cords to connect to a TV, you won't be able to see anything on the television screen. Often this is because your PS3 is sending an incompatible video signal, such as a high-definition picture to a standard-resolution RCA or S-video connection. If you reset the PS3's video output, the console will use a standard video output that your TV can accept. First turn off the PS3 by holding down the power button until you hear the unit beep; when the console's indicator light turns red, the unit is off. Now press and hold the power button again; the console will turn on and beep, but you should continue holding the button until you hear a second beep. The second beep indicates the PS3 has reset its video output, and you can stop pressing the power button then.
Safe Mode Reset
In a few rare cases, you may need to perform a reset in "safe mode," which helps recover from a major system error. This is usually necessary if your PS3 is unresponsive even after you turn it off and back on. Turn off the PS3 by pressing and holding the power button until the system's indicator light turns red. Then press and hold the power button again; continue holding it while you hear an initial beep, a second beep and a third beep. The system will power down. Repeat the process one more time: hold the button down as the system turns on, and continue holding it while you hear the single beep, another beep and then a double beep. Follow the instructions on your TV telling you to connect a controller with a USB cord and press its PS button. Select one of the onscreen safe mode options. "Restart System" simply turns off your PS3 and then back on. "Restore Default Settings" turns the PS3 off and then on and deletes your PSN account information from the hard drive, though your account is still safe online. "Restore File System" makes your PS3 check its drive and attempt to repair files or delete corrupted data, which may result in the loss of some files. "Rebuild Database" is a lengthy process where your system deletes customization settings and works through all its saved data again.
Full System Restore
This should be your absolute last resort. If you restore the PS3 system, all the data on your hard drive will be permanently lost; this includes all your game saves, music, photos, themes, videos, settings and account information. Your PSN account will still be stored online, of course. If possible, you should first perform a system backup using the "Backup Utility" located in "Settings," then "System Settings." To do a full system restore, turn off the PS3, and then hold down the power button until you hear three beeps; you'll hear one immediately, then another in a few seconds and then the third in a few more seconds. Then the system will power down. Press and hold the power button again; you'll hear the initial beep, a second beep, and finally a double beep. Connect a PS3 controller with a USB cord and press the PS button, as the instructions on your TV screen state. Then select the safe mode option "Restore PS3 System." This reformats your hard drive, deleting all data on it and reverting the console to its initial factory settings.