The final thing you can try is to get a tape taken some time ago and see if that plays back, as you will really need to determine if the problem is one of "not" recording, or alternatively a "non playback" of what has been problem, which of course the previously recorded tape test will prove one way or another. If by any chance an "old" previously recorded tape doesnt play back then the only thing you could try is "wet" cleaning of the video head, and full instructions can be sent should this be required, the info containing a JPEG attachment for illustration purposes. Should of course a proper head clean not make any difference then that can indicate a somewhat more technical reason for the fault, like for example the video head becoming defective, which of course will also affect the audio as it also comes from there. It would also be interesting to know if you have just purchased the device second hand? as if you have the video head could have been previously damaged by improper cleaning. (all of these things need asked for diagnosis purposes)

Have you verified that the tape is actually turning when you are on record, and does it play back previously recorded video? (video taken in the past) Although it should show a warning on the screen, but just in case it doesnt have you made sure the cassettes protection tab hasnt been moved to "on". Can you see images OK in the LCD / viewfinder of what the camcorder is pointing at?