Rewinding cassettes used to take a long time, until Jet-Rewind mechanisms became common, enabled by microprocessor control and detection of differences in rotation rate between the two reels. It can be considered a little harsh on some cassettes, but time is precious! I struggled to lift those early ones, and they were warm and jam packed full of stuff.
Underneath the transport itself is the rest of the logic that runs the VCR. The transport itself is the centre sections — the reel drives are in black. The eject motor is on the right side corner.
The black rubber pinch roller and capstan make up the rest. The component in black is the linear erase head. The tape runs by this head first, which erases the tape in a vertical band across the tape.
This is necessary when re-recording over existing footage. There is also a hole in the metal plate where the end of tape sensor is. The left guide can just be seen in the foreground, which has the vertical roller keeping the tape tensioned across the erase head, and the angled pin which wraps the tape at an angle across the drum. This is the drum assembly. These heads protrude very slightly from the surface of the drum and scan the tape.
The drum itself is driven by a direct drive motor above, which is very similar to what floppy drives use. The second guide roller is seen, and the reverse happens in this roller — the slanted tape is pulled back to vertical to pass the control and linear audio head. There is the control and linear audio head with the blue connector above. The tape then passes the guide pin and has its speed controlled further by the capstan and pinch roller before being wound back onto the take-up reel.
This is the infrared LED which protrudes up from the base into the cassette for the end of tape detection. This appears to be a special LED with one emitter but a lens on both sides so that infrared emanates both toward the left and right. Here you can see how the tape wraps around the drum.
The grooves in the spinning section of the drum help to control the air bearing that keeps the tape flying just above it.
This appears to be an audio head because it appears to be a single head. Remember, you cannot see the gap visually as it is so small , but you can see the head chip itself, and the coils which sense and record.
This is a pair of video heads, by the looks of it. Notice how it looks like the above structure, just narrower, with two side by side?
There is a gap between the two heads … you can see some oxide collecting. The other pair of video heads looks like this …. Again, the wear is apparent, as is the oxide. This is why you have to clean your heads … the oxide buildup can clog the head gap or alter its magnetic sensitivity. Rather unexpectedly, as a technology, it lived a long life and was a consumer revolution, and it bought me many hours of entertainment as well as a few things to do rewind tapes, clean heads, etc.
I actually enjoyed reading the manual to the VCRs — that might have been just one of the reasons I ended up as a tech-person. Luckily, there are quite a few good resources online that still cover these aspects — the next wordy post will look at some of the technical aspects. Thanks for that I was never interested in them when they the state of the art technology but now I realise just how amazing they are and spend a lot of time trying to bring discarded ones to back to life Roy.
Very nicely done. Now most are in need of some love and a good refurb or service at the very least. Thank you so much! In my class we are studying reverse engineering and as a last minute thing I chose the VHS cassette.
This has helped alot. I am so glad I found this. Thanks again! Great explanation — thank you!! Just one question: Which kind of metal is the roller of the VHS made of? It is not magnetic but rather heavy to be aluminum. Any idea? Unfortunately, I opened my VHS cassette before checking how to do it.
This presentation was a tremendous! Very well done! Splicing the tape was easy compared to putting this thing back together.
I HOPE! I certainly learned the correct way to open should this ever happen again! My Vcr is a Sony, and it keeps making a clicking noise. I think this VCR has a Sony mechanism. I still use mine all the time. My question is this. What did you use to clean your heads? Ive seen many articles saying you should use this, and avoid that etc.
Nobody seems to know for sure. For home users wanting to clean their heads and are willing to open the machine, they can use some low lint tissue such as Kimwipes, folded into a pad and dipped into high purity ethanol. The technique is rather easy to master, but you should exercise caution. Always swab the heads in the direction of tape travel, and never perpendicularly as this can cause the head chips on the drum to snap. The swab should have the cleaning solution on it, but not so much as to be dripping or oozing.
Be careful as your swab may pick up grease from the mechanical parts of the machine. I normally will dispose of this first swab and use a fresh one to clean the video heads.
The video heads can be cleaned first by holding the swab onto the drum lightly with a finger, and spinning the drum around a few times with the other finger. Preferably only touch the drum by the top edge.
Once the heads have passed the swab a few times, I would then proceed to also lightly wipe the drum to make sure the tape-facing surface is free of any finger oils. Leave the heads for a minute for all the solution to evaporate.
Of course, many users were not willing to do this, so they resort to head cleaning tapes. Another type is dry head cleaning tape which is black and appears similar to regular cassette tape, but is instead mildly abrasive and scrubs the head clean. A lack of care in using this type of tape will cause premature head wear. Thanks for the great reply. What you have said fits with the research i have done on the subject.
When looking around I found something called Chemtronics Chamois Tips. Made specifically for cleaning video, and audio heads. Its a synthetic chamois material, and meant to be very good.
When I do get round to cleaning, I think I will go for that type of product. As you say, you do not want anything which leaves fibres. Therefore getting caught in the tape transport system, and the heads themselves.
This is a great article. I very much enjoy taking apart electronics, and taking apart the VCR was pretty exciting. Thanks for the great work! Excelente information! Are you sure the control is the bottom magnetic and is not the upper? It seems there may be a bit of confusion. Gough- the control track and linear audio heads ARE on the bottom of the tape. I was factory certfiied by hitachi, matsushita, mitsubishi, jvc, sony, beta, rca,zenith,phillips,philco,magnavox,syvania,sanyo-fischer, and many others.
Im trying to fnd a plastic part for my old vcr. Its the white semi gear that guides the tape back to the rubber roller on the right side of the machine. So far I have tried gluing and re-enforcing the broken part back on but have been unsuccessful at doing so. It works one time and then the tiny section breaks off again. I wondered if there is a way to make a mold and then pour plastic into it to make a new part? Any ideas or advice would be greatly appreciated.
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