try this,
Go into setup and set up parental lock then exit out
Press OK button then RED for all services
Scroll throo till you come 2 anything you dont want to see
Press the MENU button and scroll to LOCK Do this for all the channels you dont want
Then go back to the SETUP menu into parental lock and press the green button to save it then EXIT out
All the channels you set have now gone
Press button on front of DM500 and hold for several seconds
Now when you press the RED STANDBY button on control you can take the plug out and when it restarts its just how it was with the channels still hidden.
