Problem with VCR - Worn heads?

[zilog jones]

I'm getting this annoying noise when playing some tapes on one of my VCRs. Here is a sample:

http://www.skynet.ie/~zilog/video/noise.avi

I'm talking about the small intermittent white horizontal lines in various parts of the picture. These may stay in one place for a up to a few minutes, or slowly move across the screen, e.g. the line in the lower left moves to the left edge of the picture then disappears after 30 seconds, and the line in the top left turns to a small dot and also scrolls left then rolls over to the other side of the picture and becomes a large white line again after about 3 minutes.

Could this be the sign of worn video heads? Some tapes play fine, and sometimes if I try one tape several times it will not show this noise after a while. They play fine on other VCRs. I've tried cleaning the heads (properly with chamois sticks and IPA) and it has made no difference, though the upper cylinder looks rather dirty and scratched no matter what I do. Any ideas?

The VCR is a JVC HR-S7000 (not the original 1987 model, it's a PAL model from around 1996), which I bought second hand on eBay.

[Ghitulescu]

If these tapes play with no "noise" in other VCRs, then it's a problem of your VCR.

However, it is difficult to diagnostic this error, since not only dirty heads are producing these white spikes, but also a broken head amp or an old tape. If the "spikes" are in the same place then it's a problem of the tape and the other VCRs are simply masking it (by AGC or the internal line-TBC). To identify the cause it's useful to have see the color part, not the black one. Because a dirty head will leave "traces" easily to recognise in color, also the head-amp that alters the colors, and the line-TBC, if present, will "scroll" like a wave top to bottom.

Try capturing the tapes with the VCR you like.

[zilog jones]

Thanks for the info. Are these traces you speak of look like blocks of colour around the the noise? That often happens too. I can post a sample with colour if you want. I don't think the noise is always in the exact same place but it's often in similar areas (probably on the same line at least).

That tape was from the late '80s. Newer pre-recorded tapes are usually OK but home recordings can go either way. That VCR doesn't have a TBC.

[Ghitulescu]

Thanks for the info. Are these traces you speak of look like blocks of colour around the the noise? That often happens too. I can post a sample with colour if you want. I don't think the noise is always in the exact same place but it's often in similar areas (probably on the same line at least).

That tape was from the late '80s. Newer pre-recorded tapes are usually OK but home recordings can go either way. That VCR doesn't have a TBC.

There is one more cause - electrical interferences (kitchen mixer or vacuum cleaner, motorcycle nearby etc.). Use another VCR if you're happy with its result.