OT: Bad tape or bad heads?

overyonder wrote on 10/26/2008, 3:27 PM
I just got back from a short shoot and find that my first 2 minutes is black and no time-code, then TC kicks in, beginning at 3:10, and has 5 grey bands running horizontally, along with various pixelations, then at 4:50 it suddenly looks fine. How very unfortunate. I then ran a mini DV head cleaning tape through it, which didn't fix the playback. I had used this head cleaning tape maybe 3 cassettes ago.
Then I went back to the beginning of the tape and recorded a few seconds where before it had been blank, and I got regular playback from that.

Then I went to the grey band section and recorded over it for few seconds - the camera then warned me that the heads needed cleaning, but it did record those few seconds OK.

Getting that message - the "heads need cleaning" - after I had just cleaned them, makes me think that the tape may be to blame??

This is my first experience with a major screw up.

Also wondering how often it's good to run the cleaner-tape, (it's a canon). The instructions say "it does not damage the heads" but also says "do not use excessively". I also wonder if this thing is cleaning both record and playback heads even though I only "play" the cleaner-tape....?

The recording is on a "Sony Premium DVM60 ME"

Thanks for your input
--
John

Comments

John_Cline wrote on 10/26/2008, 4:21 PM
Sounds like it's probably a bad tape.

Regarding the head cleaning tape; as the instructions point out, it's not a good idea to use it too often. It is mildly abrasive and will shorten the life of your heads if used too much. Only use it when you have to, like in the situation you described. On a DV camcorder, the same heads are used for recording and playback.
johnmeyer wrote on 10/26/2008, 9:33 PM
I have had this happen, off and on, with my original Sony DV camcorder (TRV-11). The headcleaning tape sometimes helps, but not always. I have had it happen with many different tapes. While I think it may be a head clog, I don't think it is the kind of thing that is usually helped by head cleaning.

In my camera (which I still use), I found something which usually works.

The first thing to try is to remove and re-insert the tape. Then try again.

The second thing to try is to put a different tape in the camera, record a few seconds, and then rewind and play back that footage. Do this 4-5 times. Most of the time, this will fix the problem.

The final thing to try is to simply fast forward (not while playing, but by first stopping the tape and then fast forwarding), and then when you get to the end of the tape, rewind it. No try again to play back the tape.

See if this doesn't help. Sometimes the tape is unreadable, but sometimes the video is actually there and you can capture the tape.



baysidebas wrote on 10/27/2008, 5:37 AM
I have recently come across a similar problem on my 3 PD-150s. All 3 cameras, after working with no issues using Sony Premium grade cassettes, immediately upon use of Excellence grade cassettes display the heads need cleaning message. Without cleaning the heads, but resuming using Premium cassettes the msg goes away and recordings are flawless. It's got me scratching my head, this one.
overyonder wrote on 10/29/2008, 7:52 AM
Thanks for the comments.
So I put in the head-cleaning tape one more time and no longer got an onscreen warning.
Another forum post said you can get problems when you switch to a different type of tape. That your heads somehow become accustomed to the formulation of the tape and that when you switch, you might want to run the head-cleaner as a kind of fresh-start. Sounds odd to me, but apparently it's worked for others.
The post that the data might actually still be there is interesting - I'll check it out, and if it comes back I'll be sad I recorded over a few seconds of it for my test, but this is good to know.
--
John
baysidebas wrote on 10/29/2008, 8:50 AM
John, it's always been my feeling, although not confirmed by others, but based on my near 35 years experience with videotape, that you'll detect dirty head problems on playback long BEFORE recording is affected. The reasoning behind that is that the playback signal is orders of magnitude weaker than the recording signal. So if the weak signal is affected, the recording signal may still able to punch through the head clog [as long as it isn't too bad a clog]. So it's always good practice to do a short test recording, or even just a playback, before starting a shoot. Then, even if heads develop a problem during the shoot, you may not have to stop things for a head cleaning, indeed, you may not have that option available to you.