Your PS3 must be wired, it will not work if you're using WiFi
Ok first, start ProDG Target Manager and go on "Search For Targets" then press the refresh button to start scanning, if all is ok your PS3 should be detected, just right click on it and move it to "Debugging Station" group then double click on it, it will add your PS3 into your targets list.
60w ago - Recently yayes of PS3ISO (linked above) shared a PS3 CEX to DEX to CEX tutorial and file pack for those interested in converting their PlayStation 3 CEX (Retail) console into a Debug / Test (DEX) unit and then being able to revert it back.
Below are the details from the file pack for those interested, as follows:
WARNING!! Backup your CEX Flash Dump!! Don't Deleted it or You in DEX Forever. (Update: A Solution is now posted by haze67).
I'm not responsible for any problems/bricks the members suffer and that they'll do it on their own risk. Make Sure You don't Have Spoofer Installed.