On the Samsung LE74 series the following (see box below) allowed access to the Service Menu. I don't know if it's still the same on their latest models.
Quote:
“On your remote press “Power Off - Info - Menu - Mute - Power On” (if You can't get it to work try doing it slower). Your TV should turn on with purple Menu options.
*** Warning - don't mess with unless you know what you are doing! ***”
