I have installed a converter box we have a rooftop

If you have the converter connected to the recorder by composite or s-video(line inputs), you will need to specify which jacks from within the setup menu of the recorder. There are 2 sets of line inputs into the recorder, so you have to select the right ones. They are called L-1 and L-2. The L-1 jacks are in the rear and the L-2 jacks are in the front. The channel selection should also be on L-1 or L-2. If you are using the
RF input(fat cable) to the recorder, you should have the recorder on the channel number that matches the output of the converter (channel 3 or 4). The converter RF output is selected by a switch in back of the converter or by the setup menu of the converter.

Menu path for setting L-1 or L-2 inputs:
Setup > General Setting > Video > Video Input > L-1 or L-2 > Video In or S-Video In