Has anyone done any service level tweaks to this set yet? This is my first rptv & I already downloaded the service manual but I've never tweaked beyond the user menu. I've already navigated around a bit in the service menu to get acclimated but of course didn't change anything, yet! This is probably a dumb ? but what is the monoscope signal that the manuel keeps refering to? I've only had the set for 6 days so it's not really broken in yet but I'm anxious to get started, any suggestions?