Panasonic DVD Recorder DMR-EZ45VEBS not recording?

Can you help us please. We have a Combined DVD/VHS Recorder Model DMR-EZ45VEBS. We have had this unit for several years operating without any problems.

We now have problems recording on DVD or the Video. On the front panel, it appears to be recording with the time counter operating. When you try to playback (via functions), the screen windows are black (although the title is below each window). Attempts to playback, just give "no signal".

Existing pre-recorded DVD's and videos (that we have recorded previously) play normally. The TV, fed by its aerial cable via the Panasonic, is working perfectly so it is getting a signal.

We have tried recording on several different DVD disks but they are all giving the same problem.