Some combinations of devices (e.g. DVD players, VCRs, TVs, Sky boxes, etc) allow the receiving device (in your case, the TV) to recognise the presence of an incoming signal from the sending device (the VCR with your set up). Other combinations require the receiving device to be told to accept the incoming signal.
Check that the TV is not switched to any numbered channel. It needs to be switched to 'AV' or whatever other label your particular handset uses for this function. (It might be 'AV1', 'AV2', 'Line In', 'L1', 'L2', 'Ext', 'Aux' or something else similar).
Chris