Instructions
Abort the downgrade attempt by pressing the "Circle" button. This will take a few minutes as the downgrade will attempt to reverse any changes it has made.
Turn off your PlayStation 3 system. Restarting the system can wipe its short-term memory clear and give the system a fresh set of files to work from, which can be useful if one of the files temporarily became corrupted.
Reconnect the peripheral performing the downgrade. If you are attempting to install the downgrade file from a USB port, ensure that the USB disc drive is plugged into the console snugly.