Hi Matt,
As you have the service manual, can only point you to the page about the Self-Check Mode. If you enter the self check menu, check any items marked "NG" = no good. Not expecting any, but when you exit the mode it will automatically carry out a factory reset. When you turn it on again, you will find it in the state it was in when first unpacked. Just follow the prompts on the screen. Hope that restores EPG and clock data.
Bruce