I own a Canon GL2 that is about 3 years old and I have put at least 100 hours of recording time on the tape heads. This weekend, I shot about 10 hours of footage on 10 separate Mini-DV tapes. When playing back the tapes today, 3 out of the 10 tapes play back as nothing but digital pixelated noise with no audio. Let me make myself clear: I have played these tapes in 2 other cameras of different make and model, AND I have cleaned the tape heads on these cameras numerous times before and after attempting to play these 3 tapes. But they just won't play properly. I called Canon's tech support line and they think it's something with my GL2's recording head. But could it just be a bad batch of tapes? Can anyone help me out here?
Unless the tapes were 1,2 & 3 or 8, 9 & 10 you're probably right in that there is something wrong with the tapes and not your camera. If you can't get anything off them, toss them and reshoot. There's nothing else for it.
If, however, you can play back from any point of the tape, pull what you can, and hope for the best. I had a bad tape this weekend cause me an extra 9 hours of editing on a show that I normally don't spend 9 hours from shoot to final tape delivery, so I feel your pain. But what else can you do?
if a part is worn on a camera, it generally degrades over time, not has a bad day then works, then doesn't another day a week later. Just my experience, YMMV.