The read/write heads are located on the VCR drum and they cannot be cleaned using a cotton swab or you will damage your VCR. On Figure 8 you see the drum and two of the read/write heads. If your VCR is a four-head VCR, you will find four of those heads there.

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Figure 8: Drum. The red arrows point two of the read/write heads.
To clean the read/write heads you will need a 1.5” x 4” (3.5 cm x 10 cm) piece of paper. Just get a blank sheet of paper and cut it.

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Figure 9: Pieces of regular blank paper are used to clean the heads.
Get one piece of paper and wet half of it with alcohol.

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Figure 10: Pour alcohol on one piece of paper.
To clean the heads you should put the wet piece of paper on the drum and rotate it counter-clock wise several times.
Now let’s talk about the incorrect way of doing that. You cannot do like we show on Figure 11 or you can damage the heads. The correct way we show on Figure 12.

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Figure 11: Incorrect way of cleaning the heads.

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Figure 12: Correct way.