A few words of thanks would be greatly appreciated.

How To Install a PS3 Update Via a USB Key

Is your PlayStation 3 having trouble connecting to the internet? This article will show you how to update the firmware manually. You can download and transfer the update file (PS3UPDAT.PUP) using a compatible storage device such as Memory Stick, Memory Stick Duo, a USB key (FAT32) or PSP.

How to install a PS3 update via a USB key

Prerequisites

A USB key formatted in FAT32.
Create a PS3 folder at the root of your USB key.
Open the PS3 folder and create a UPDATE subfolder.
NB: The folder names are case sensitive.

Procedure

Download the latest update (4.70 24 February 2015) on your PC: http://us.playstation.com/support/systemupdates/ps3/
Transfer the PS3UPDAT.PUP file to the UPDATE folder.
Connect the USB to your PS3.
Go to Settings > System Update, then Update via Storage Media.
Select the USB key and launch the update procedure.