Last night I popped a tape in the VCR and when the picture appeared, it was black and white. I stopped the tape, and the TV picture was in color, as normal. I restarted the tape, and it was black and white again. I had to turn off the VCR completely and repower it for it to operate normally. I rewound a bit and rewatched the part that had just appeared b/w, and it was normal, so it’s the VCR, not the tape.
This was a tape of some shows I’d recorded off my TV, and I have watched the tape before, and it looked normal every other time.
Anyone have a clue why this would happen? Does it mean my VCR is about to die?
When I serviced consumer electronics my specialty was audio, but I was close enough to the VCR guys to hear them mention this problem a few times. Apparently the chrominance (color) signal is the hardest for the video heads to read, so in the event of dirty heads or a slightly mis-aligned tape, the C signal is the first to be lost. If your VCR has a manual tracking control you might be able to demonstrate this by mis-adjusting the tracking until the picture starts to suffer… the color should be the first thing to suffer.
It’s possible that the tape was slightly mis-aligned and ejecting it & reloading it allowed it to be better “seated” in the mechanism. Or you might have dirty video heads in which case it’s time for a cleaning. In the latter case, the problem will re-occur more & more often as the heads collect more crud.