Hi
Use your philips remote and enter 062596 followed by the text i button this will enter the service menu.
Please note ...Take a copy of the settings before changing anything as these set are a pain to set up if the setting are lost . (I should know because I have changed a lot of processors on these sets and the odd time the eprom settings get reset and if you dont have a copy of the settings you can say goodbye to an hour)

Regards
Andy

BTW you have to put the set into stand by to exit service mode