JVC VHS VCR full mechanism tear down and reassemble

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  • čas přidán 7. 06. 2015
  • Tear down, lubricate and reassembly of the popular JVC HRD870 mechanism.
    Many different models use this popular mechanism.
  • Věda a technologie

Komentáře • 133

  • @karthick86c
    @karthick86c Před 4 lety +4

    Thanks a lot for going into the details of the VCR mechanism. For the last couple of days I have been scrounging the internet for this information.

  • @jamesdemuro5923
    @jamesdemuro5923 Před 7 měsíci

    The Master of vcrs repair of all time 👍Thank you for all the valuable information on this machine JVC and all the others .

  • @zulumax1
    @zulumax1 Před 3 lety

    Best training video on VCR I have seen so far. Liked this one better without that generic background music. The dogs barking, airplanes, heater turning on just added character. Going to have to watch this one a few times to absorb it all.

  • @Okie-Tom
    @Okie-Tom Před 7 lety +1

    Very nice demonstration of the tear down and reassembly. Always those little tricks to learn. Thanks.

  • @ronniepirtlejr2606
    @ronniepirtlejr2606 Před 4 lety +3

    There is some pretty amazing technology in some of those older VHS players!

  • @robertmattison1282
    @robertmattison1282 Před 7 lety +6

    Just want to say, thank you for making this video.

  • @DrewMcConnellYama
    @DrewMcConnellYama Před 2 lety

    I still can't get over the epic intros. Awesome video!

  • @lstein3372
    @lstein3372 Před 4 lety

    So much great information in this video. Thank you so much. The mechanism designers of these devices must have been treated like rock stars in the industry. So complicated.

  • @helioribeiro7
    @helioribeiro7 Před 6 lety +5

    Very Thank's! you video help-me a repair JVC HR-VP616. thank's from Bahia, Brazil. I love VCR's

  • @ngl-kd7tn
    @ngl-kd7tn Před 9 lety

    Superb video of the inside workings of a video player/recorder. Very well presented and explained with plenty of detail. Well worth watching. Thanks for taking the time to make this video. Cheers.

  • @aboodissa9189
    @aboodissa9189 Před 9 lety +2

    I'm very happy and grateful also for its wonderful work
    Thank you very much:)

  • @avanolafernandez3587
    @avanolafernandez3587 Před 7 lety

    easier said than done!! an expert enjoying what he does best :)

  • @jark9705
    @jark9705 Před 4 lety

    Thank you very much for your helpful videos. Now my hr-j 620 works again! It was an issue with loading/unloading the cassette. The spring was loose.

  • @italovalerio
    @italovalerio Před 3 lety

    Love this video, thank you very much.
    The mechanism is the same of JVC HR-S6600U (1990) and i'm doing a maintenance on this.
    Using 2 VCRs i'm using some parts from one to other.
    solved:
    Instable video heads (play video ok, stop, play again video with all noise, stop, play again video half ok and half noise...) : Drum
    but now the gear on capstan and the gear (yellow that you show in 12:15) broken 3 theet on part of connection to blank gear. I will try recovering with a glue. I'm search this gears but i not found.
    The HR-S6600U have a very impressive quality of sound and video especially with SVHS recorded.

  • @bernardwright2255
    @bernardwright2255 Před 4 lety

    A found this is very helpful. I have a different VCR but the principle is the same. Service manuals are related to the elusive chook. Cheers

  • @donald1056
    @donald1056 Před 8 lety

    Tedious work!!

    • @12voltvids
      @12voltvids  Před 8 lety +2

      +Donald Ellett This is easy. Try working on a portable DAT or a DV camcorder. Now you are talking small parts.

  • @RolandV3922
    @RolandV3922 Před 6 měsíci

    Very informative. Thank you sir.

  • @user-jl6yp8zr8w
    @user-jl6yp8zr8w Před 9 lety

    Hi from Greece my friend. Thanks for the very good videos.
    I do have 2 JVC vcrs one HRD 720 and a HRD 520.
    I cleaned both mode-switches after watching your previews video on how to remove the switch the easy way.
    Now something about JVC HRD 520. I gave this vcr to a friend, who stored in a loft.
    There was water leakage for about 3 months so the vcr was in dirty water for that time.
    When he gave it back to me it was rusted allover.
    I didn’t throw it away but i dried to save it.
    I cleaned it internally, lubricated it and YES it worked.
    There were problems of course like strange noises from the drum, front panel switches not 100% functional and there was no color in picture, but nonetheless it worked.
    Also something else about belts.
    There are some belts like those the jvc vcr of that time had that don’t deteroriate. The do have the originals (I mean the rubber ones, because the plastic with teeth are from different material and are life time)

    • @12voltvids
      @12voltvids  Před 9 lety

      Στολης Επισκεπτης Yes the nylon toothed belts last a long, long time. Neoprene belts also last a long time. Natural rubber ones oxidize and melt from ozone in the air.

    • @supermasterPIK
      @supermasterPIK Před 8 lety

      Do you buy belts at studio sound electronics??

    • @12voltvids
      @12voltvids  Před 8 lety

      There are a few local electronics suppliers that have limited belts. The last one I needed new was for my Tascam DA40, and I ordered that one directly from Tascam.

  • @ulhassavant6968
    @ulhassavant6968 Před 4 měsíci

    Appreciated sir.

  • @mikedrz
    @mikedrz Před 7 lety

    Thanks for your videos, I've got an old JVC HR-VP612U that I've been trying to fix for days now. I've watched hours of your videos and got it to the point that it no longer chews up tapes. Now it just loads the tape and either immediately ejects it, or it just half loads it, and won't play the tape. It gets to the point where the pincher is about to come down and then aborts. Funny enough though, the pincher will come down to rewind the tape sometimes. Not sure where to go from here, already cleaned the mode switch.

    • @mikedrz
      @mikedrz Před 7 lety

      Fixed it, it turned out to reject the tape because of light getting on the sensor. I tried it in the dark, and it fired right up. Now I just have to fix the door, it's not opening on eject.

  • @ReDRuM868
    @ReDRuM868 Před 6 lety

    Thanks so much for this video and the other one of this unit. Got an HR-D860U for Christmas and had most of the common problems you mentioned. The bottom retainer on the roller guide was missing, one guide pin missing, the cracked gear on the capstan motor and the bad capacitor on the head drum. I never could have figured out that problem with the bad capacitor on the head without your video. I replaced it and now its working great and has an awesome picture. Only thing wrong now is the remote control for some reason pauses the tape no matter what button you press, and some buttons dont seem to work at all, but the power button works. The red light also seems to flash really fast when you press a button im not sure if thats normal. I took the remote apart and I don't see any obvious problems. Wondering if maybe you could give me some idea of what the problem could be.

  • @tuberworksjones
    @tuberworksjones Před 8 lety

    Makes its look easy .

  • @engine002
    @engine002 Před 7 lety

    thank you guy for help me i wached serial video i from brazil

  • @jeffers2006
    @jeffers2006 Před 5 lety +1

    Great video
    I’ve got an old JVC HRS5000EK
    It won’t load the tape unless you manually push it in it will only eject tapes automatically the mechanism is fine and the motors all work but I’ve noticed it’s showing a tape is loaded when it’s empty
    The take up guides and rollers are in the load position but don’t move
    If I rotate the motor they do move back and will return using the motors when it resets
    Any ideas?

  • @zulumax1
    @zulumax1 Před 3 lety

    2:05 The loading mechanism on that rear motor is jammed on mine, so that gear on the cassette eject would not turn without removing the belt. I don't know why they did not make these more standardized even among the same manufacturer. My SVHS has one screw in the rear and two (or more?) from the front, not the top, behind the display board which must be removed to gain access. It could be the same as this one, will have to give it a second look. I was working on it and my shop chair spun around when I stood up and hit the green family message led and broke it off. After few choice words said, I realized that is a feature I will never use, so I just removed the broken led. Good thing it is my personal unit and not someone else's I was working on.
    My daily driver VCR is a JVC HR-XVC26U with DVD player from 2004. Paid $12 for it at a thrift store, the VCR doesn't miss a beat, but the DVD is problematic. Don't care about that anyway because it was a bargain as a VCR only.

  • @emn8or
    @emn8or Před 3 lety +1

    Great video mate, thanks for this. I have a JVC HR-J615EA that the tray doesn't lower or load the tape 100%. From what I see in your video at around 8:00 I'll have to take the tray assembly out to fix it? Or is there another/simpler way to adjust or properly align the loading gears? Thanks in advance

  • @supermasterPIK
    @supermasterPIK Před 8 lety +1

    In my country (South America) technicisns don´t want to check Beta machines ... So i´´l do it. I like buy these machines and restore them up.

  • @AliPawan
    @AliPawan Před 6 lety +1

    Hey 12voltvids I have a Aiwa MX100u and removed the loading mechanism, now when I try to reassemble the mechanism it is not working. It seems like I am aligning my gears up incorrectly and therefore they aren't gripping like they should. Please help, any advice would be appreciated.

  • @InsideOfMyOwnMind
    @InsideOfMyOwnMind Před 8 lety +1

    Loading the alignment reference tape on the first mech test? Brave.LOL I serviced all brands of vcrs 40Hrs./week through the entire vcr hayday. I would have caught some crap for that even if I won the bet like you just did. If I had done a lot of work to a mech I used to start with the two finger loading blocked optics method, then a skeleton cassette then a B movie. Don't take it badly. The video was a great demonstration of what goes on (went on) inside of The Beast.

    • @12voltvids
      @12voltvids  Před 8 lety

      That is a test tape. That's what it is for. I record my own test tapes. I have a factory alignment tape safely stored somewhere. I make my own alignment tapes on a machine that I have verified as correct with my factory tape, so that tape has little value if it gets chewed. I have a color bar generator built into my broadcast camera so it is easy to make another one. Just plug the old camera into a know good VCR and hit record.

    • @InsideOfMyOwnMind
      @InsideOfMyOwnMind Před 8 lety

      It looked about as good to me as any legit alignment tape I've seen except of course for U-matic. Even the fact that it was on a short 30min? tape. Fooled me good.

    • @12voltvids
      @12voltvids  Před 8 lety

      Yes 30 min, large hub. I used to buy all different lengths for duplication projects.

  • @kenth8341
    @kenth8341 Před rokem

    I need advice. I'm working on a similiar unit now HR-D930U to try to fix. I know now the original problem was a gumed up forward and reverse main gear drive post and a leaky main power supply cap which I fixed. Also cleaned the mode switch with D100 all stuff Ive learned here from Dave. Now my problem is after reassembly the unit shows a eject status at powerup with no tape in and then shuts off immediately. During the few seconds its on the worm gear is trying to run but doesnt. Ive rechecked the mode switch for notch allignment is good and alignment for the holes in gear next to the worm gear also good. What did I break? The basket works out of the unit but there is a small spring i found loose not sure where it goes somewhere on the left side pretty sure. Not sure if its critical or not. Appreciate any thoughts.

  • @rsattahip
    @rsattahip Před 6 lety

    Electronic troubleshooting can be fun, but messing with those mechanical/electronic devices is just plain miserable. Thanks for posting.

  • @capdefensor
    @capdefensor Před 6 lety +1

    12voltvids, I have a JVC HR-D651M VCR (that uses the same mechanism of HR-D870) which has a follow fault: it's display turns off seconds after press power button. Do you have any idea what might be happening? I have tested the power supply and it's OK, the mechanism is also OK, cause I tested it with another power supply (not the VCR supply), the cables that are connected in mechanism have continuity, are not damaged. Thanks and await the answer and sorry by possible orthographic errors (I'm brazilian and my english level is intermediate).

  • @supermasterPIK
    @supermasterPIK Před 8 lety

    Does the HR1610 UM use thiis mechanism? A model which appeared in 1992

  • @coolelectronics1759
    @coolelectronics1759 Před 3 lety

    cool video!
    one thing that has always frustrated me fixing electronics are those stupid springs! Have you ever gotten one of those things stuck in your finger? Its hell! It doesn't end there. Some are "screw one up and its game over." I hate those 360 type ones you know the kind that hold a VHS tape flap down? Do you have any videos with helpful tips on getting those back in? With the normal spiral kind I have had bad luck stretching them too far trying to reatach them. I appreciated the one video where you showed us the belt trick using a piece of tape to keep it from going anywhere. Do you have any similar tricks for when it comes to working with springs?

  • @raadharamesh
    @raadharamesh Před 3 lety

    Hello 12voltvids, Do you have a video regarding the cassette carrier linkage settings for JVC HR-P40A Video Cassette Player?

  • @supermasterPIK
    @supermasterPIK Před 7 lety

    what model is this jvc??
    i got a hr1610 UM from ....1991???
    working peeflectly

  • @vintagelover3873
    @vintagelover3873 Před rokem

    So this mode switch need to clean?

  • @rodolfonetto118
    @rodolfonetto118 Před 6 lety +1

    Hello, Sir! I asked you a question on another of your videos but I think this one has made things more clear: my JVC HR-S9911U has some problem with the clutch: when it fast forwards or rewinds doesn't do the job, makes a screetching sound and turns itself off. The unit is NOS and stayed on a warehouse for over 15 years. Everything else works. Do you think it could be just a matter of lubrication? If I disassemble the mecanist like you did to the point you arrived at the clutch will it misalign the more sensitive parts? Thanks!
    EDIT: It seems I found out what the problem is: lubricaton on the clutch mechanism and the clutch engaging lever. I'll do the appropriate repair and post the results later. Thanks, 12V!

    • @EricKotter
      @EricKotter Před 3 lety +1

      Did lubricating the clutch work? I have a similar problem on my JVC SR-V101US. It won't fast forward or rewind very well. When you hit the rewind/fast forward button, it makes a terrible screeching sound as it tries to rewind quickly, then it slows down to a slow crawling rewind/fast forward. I'm thinking it's a clutch problem. The tape plays normally.

    • @rodolfonetto118
      @rodolfonetto118 Před 3 lety

      @@EricKotter I ended up taking it to a repairman that still works with VCRs - har to find even in Brazil and I was lucky because he only works for a few people. He has hundreds of old VCRs and takes parts from them. In my case he had to replace the clutch - he's a perfectionist, though.

  • @supermasterPIK
    @supermasterPIK Před 8 lety

    Also I have the HR2200 UM (" portable " unit) Can you help me also. Thanks.

  • @alanwong3980
    @alanwong3980 Před 8 lety

    hello 12V, Thanks for this video I got my JVC fixed(partly). I fixed the mechanism and clean head drum. But I hope you can advise me on the video show the top 80% and the 20% is snow and the no HIFI sound. Which section should I look at it?
    Regards
    Alan

    • @12voltvids
      @12voltvids  Před 8 lety +1

      +Alan Wong Sounds like either an alignment problem of the tape exit guide on the drum (the guide pin on the right side may be loose, and causing a mistracking) or the coupling capacitor in the PG circuit could be open. I have a video on that one. There is a smapp electrolytic capacitor mounted on the drum motor stator board that couples the PG pulse from the PG coil on the drum motor boare through to the head switching IC. I did a video on that. It causes snow on the top or bottom half of the picture.

  • @packratswhatif.3990
    @packratswhatif.3990 Před 6 lety +1

    What is your all time favorite mechanism for any VCR system ? Also, what about DAT mechanisms ... thanks again ....

    • @12voltvids
      @12voltvids  Před 6 lety +1

      Oh that one is easy. Sony 710 Betamax. Bulletproof. Never gives any problem.
      For VHS, the professional JVC and Panasonic units were dam fine mechanisms. For consumer VHS the Panasonic 1730.
      For DAT Tascam DA30 and DA40 were reliable mechanisms sans the stupid loading belt. For DV Sony had that market

  • @lakhvirdhaliwal2126
    @lakhvirdhaliwal2126 Před 4 lety

    Sir I have national g500 vcr .I face problem is while in play tape counter not ???

  • @videovintage6247
    @videovintage6247 Před 4 lety

    Hello!
    I need help repairing the mitsubishi hv v7000 power supply, I need a power scheme, capacitance ratings and resistance.

  • @supermasterPIK
    @supermasterPIK Před 3 lety

    1992 HR 1610 model?

  • @aar7790
    @aar7790 Před 4 lety

    Grate from persian

  • @rugbygrange
    @rugbygrange Před 7 lety

    Hi - thank you for this informative video; quick question: I have a very well kept Toshiba that just started not working because (it appears that) the mechanism that winds the tape back into the cassette isn't working. It loads fine, but then stops and gets stuck (and I have to untangle it and pull it out) because the tape begins to play but doesn't wind back into the cassette. And suggestions/thoughts on what I can do to fix this? I'm so not mechanical, but watched some videos on how to get it unstuck and now your video, so I have a beginners sense of things. Thanks, in advance, for any help you can provide.

    • @12voltvids
      @12voltvids  Před 7 lety

      Well the problem will be mechanical. Worn drive belts, or rubber idler tires are the most common faults that cause the tape to not wind into the cassette.
      Dirty mode switch is another common fault that can cause tape eating.

    • @rugbygrange
      @rugbygrange Před 7 lety

      Thanks for the reply. That doesn't sound like an easy in-home fix - is it something that a repair shop could fix, or am I looking at purchasing a new one in your opinion?

  • @IREKWWSL
    @IREKWWSL Před 3 lety

    Solid mechanism on older models. The mechanism in new VCRs is delicate and susceptible to damage. Why were these changes made? It is known that every engineer has to "improve" something

    • @12voltvids
      @12voltvids  Před 3 lety

      New ones were actually more reliable due to fewer moving parts.

  • @alanwong3980
    @alanwong3980 Před 8 lety +1

    Hello 12Voltvids,I have the same mechanism. It does fastward and rewind. when i press play it eat tape.Which parts of the machansim should I look at?

    • @12voltvids
      @12voltvids  Před 8 lety

      +Alan Wong Check the clutch assy for gummed up grease. 29:20 is where the portion showing the tear down of the torque limiting clutch is shown.

    • @alanwong3980
      @alanwong3980 Před 8 lety

      thanks for quick reply. Do I need to tear off all other parts?

    • @12voltvids
      @12voltvids  Před 8 lety

      +Alan Wong You only need to take off what is necessary to reach what you are working on.

  • @darcmass3290
    @darcmass3290 Před 7 lety +1

    Hi 12voltvids,
    I was wondering if you can help me with a problem with my JVC vcr. I have a JVC SR-MV45 VHS/DVD deck and today I turned it on to transfer some tapes to dvd. I turned it on, inserted a tape and played it, but only static shows on the screen, which is weird because it played just fine a week before. While the tape is playing, the lcd on the vcr shows a "U01" error every 3-5 seconds while the timer is counting. Do you have any idea what might of happened?

    • @12voltvids
      @12voltvids  Před 7 lety

      Check to see that the tape is threading correctly. If so it could be a clogged video head.

    • @darcmass3290
      @darcmass3290 Před 7 lety

      Did a clean on the heads and played through a newer tape for a couple minutes, it looks like it have cleared. Tried my client's EP vhs tape, it played a couple minutes and started getting static again. The problem seemed to be my client's vhs tapes, they may have been very dirty. Thank god it was just dirty heads, I thought I had to dump the vcr. I think I shouldn't not push my luck with those tapes before something gets damaged. These JVC decks were the only dvd/vhs combos with time base correction on the VCR side if im not mistaken, and man it's a godsend.
      Anyway 12voltvids, thanks for your input. I always find your tear-down videos fascinating and educational, even though I'm not a technician myself. CZcams needs more vids like this!

    • @12voltvids
      @12voltvids  Před 7 lety

      Bad tapes are the #1 cause of head contamination.

  • @monanagy1637
    @monanagy1637 Před 7 lety +1

    The worst problem is when you put it in lock mode and lose your remote

    • @12voltvids
      @12voltvids  Před 7 lety

      Used to look those ones that would come in locked.
      Easy fix. I would
      unlock it, clean it, and charge them for a cleaning. The boss would get
      mad if I didn't charge more and I would say something like "what if this
      is a set up, you wouldn't want the local news cameras in your face
      would you" Because that is exactly the type of stunt they would pull, or
      stick in a blown fuse and bait the servicer and see if he would pull a
      fast one.

  • @raadharamesh
    @raadharamesh Před 3 lety

    Hello 12voltvids, I was asking for cassette carrier adjustment details for JVC HR-P40A, you had JVC HR FS1 VCR, which has a similar carriage assembly. I could repair my VCR with your video. Thank you very much.

  • @speedyboishan87
    @speedyboishan87 Před 4 lety

    You see next to the VCR heads there is a round metal object how do i attach that back to an JVC HR-S9500 SVHS VCR it has come loose, when i play a tape it plays fine, but not sure where that metal round disc goes thats next to the heads. Please help

    • @12voltvids
      @12voltvids  Před 4 lety

      That is just a tape stabilizer. Works like a shock absorber to take the vibration of the tape heads as they make contact with the tape. You don't need it. It just clips onto the roller but it is ok to remove it.

  • @crtvhs4life334
    @crtvhs4life334 Před 2 lety

    Hello sir. Those JVC roller guides are a nightmare. My take up side roller guide gets stuck and doesn't position itself in the "V" stopper. I tried everything, tightening the brass poll and the plastic part, re-greasing, no matter how hard I try it hits that metal stair or whatever it is at the end with it's tip and gets stuck. There's a video on my channel. I would highly appreciate your advice. Should I use the fine file on the tip of the pole stand or the stair beneath the V stopper? Could I damage it beyond repair that way? I saw a written tutorial on the net that suggests this method. The whole pole stand is way too loose and when it comes in contact with the tape it lifts up a little bit and hits the obstacle at the end.

    • @12voltvids
      @12voltvids  Před 2 lety +1

      Usually it is the brass base seperaring from the rest of the guide and not allowing it to slide into the v block. I did a video on this years ago. Don't ask me to search it either. You can find it as fast as i can.

    • @crtvhs4life334
      @crtvhs4life334 Před 2 lety

      @@12voltvids You were right. I was sure I secured it in place but it turned out I wasn't.

  • @davidmaiolo
    @davidmaiolo Před 6 lety

    Was this filmed and edited on VHS?

    • @davidmaiolo
      @davidmaiolo Před 6 lety

      TheAstro30 hmm, did you hear the one about the guy who threw his vcr out his upper story apartment window because it wouldn't play his DVDs? Ah, nevermind, it's probably over your head

  • @rahulray9958
    @rahulray9958 Před 7 lety

    Hi,
    I am an avid follower of your videos and really appreciate your efforts in repairing and restoring electronics especially VCR's.
    I have a JVC HR D321EM vcr and was wondering if you can provide aome insights to it?

    • @12voltvids
      @12voltvids  Před 7 lety

      Sure what is the trouble you are having?

    • @rahulray9958
      @rahulray9958 Před 7 lety

      Almost 30 yrs old now, it has issues with picture quality, tracking,speed fluctuations and intermittent video output as far as I remember.

    • @12voltvids
      @12voltvids  Před 7 lety

      If it is a belt drive unit check the belts for stretching. 30 years is an old beast. You can send pictures of the mechanism to me if you like.
      volt@telus.net is my email for technical questions.

  • @sandra2809
    @sandra2809 Před 4 lety

    Darn. I came here thinking someone showed how to get the bottom off 🤫 Cos opening the vcr is the step where I get stuck 😬😄

  • @bobsbits5357
    @bobsbits5357 Před rokem

    hi have you on when i am working on 2 betacam sp 1800 the thing is 2 can't be fixed as one has alot bad
    and one has something bad as well this 1800 has 18hrs on the head drum i payed £25 uk
    it's a lotto what you get sometimes i was hope to have one good one bad luck
    in a good way i have 2 older betacam sp decks that been sitting around for a very long time they work now ok
    the sy61 cards i had were all bad i swap over a card to test the decks they were ok
    i left them on for long time jus to see what is going on
    very likly i come in to betacam sp that has very high hrs and move hrs pcb (with the cell) and head drum
    to a better deck i have betacam sp decks that are funny about tape sizes i put a brass stop just in side the door
    so i can only put S betacam sp tape in the deck if not i can hear the gears in side say saying the arms have not moved in to place

    • @12voltvids
      @12voltvids  Před rokem

      I've never worked on betacam decks. I had an sp camera for a few years when I was shooting but sold it probably 20 years ago as i didn't have the playback decks. I just was a shooter and handed the tapes to the production guys at the end of the shoot.

  • @VIDEOHEREBOB
    @VIDEOHEREBOB Před 7 lety +1

    Wonder if you can help. Cleaned the heads, Thank you. At the very bottom of the picture I have what looks like little flickers of light at the very bottom of the screen. It's a JVC dubbing desk and this flicking happens only with VHS playback. Swapped out the LCD TV, made no difference. Any suggestions would be greatly appreciated. Bob

    • @12voltvids
      @12voltvids  Před 7 lety

      Ok what you are seeing is called the head switching point. On VHS head switching occurs 6 lines before vertical sync, and on Beta it was 7 if memory serves correct. On analog recording, VHS, Beta, 8mm, 3/4" recording is done by 2 heads. Each head records 1 field of information. In a perfect world head switching would be done during vertical interval. On NTSC that is 22.5 lines of black between each field of active picture. During that 22.5 lines is the vertical retrace pulses that signals the TV to completely blank the beam, and fly the beam from the bottom of the screen back to the top. (This is why, for example on the video I did on the shorted video output in addition to the red screen there were a dozen or so diagonal lines, as that was unblanked beam hitting the screen during retrace.) Because analog is less than perfect, a distortion during that all important vertical retrace period is unacceptable. It would cause sync instability, and a jittery or rolling picture. This is because there are slight mechanical differences between each VCR, and there are slight mechanical differences on the same VCR every time you load a tape.So the solution was to have head switching occur before vertical sync. The problem is you can see it, so where do you hide it. They could have put it after vertical sync, in the vertical interval area at the top of the screen, but that is where things like closed captions, and later macrovision scrambling signals are. So the bottom of the frame was chosen, a few lines before vertical sync starts to ensure that distortions caused by head switching don't make it into the sync area. In the days of CRT televisions, the tube was intentionally overscanned, in some cases up to 10% This was done because picture size changes with incoming electrical supply, and in the days before good regulation, when demand for electricity was high, such as when everyone is cooking dinner, the voltage would drop, and this would cause the picture to shrink. The manufactures didn't want TVs coming back for a small picture, so they made it slightly over scanned, so that when it shrunk during times of lower voltage, it would still cover the screen.Enter digital TV. Those flat panels have a fixed pixel count, and the digital electronics count every line, and display every active line on the screen with precision. Unfortunately they also display the head switching point from analog video.

    • @VIDEOHEREBOB
      @VIDEOHEREBOB Před 7 lety

      Thanks so much for your reply. I really appreciate it. So it's basically normal, something you have to live with? Will it/can it disappear sometimes depending on the tape?

    • @12voltvids
      @12voltvids  Před 7 lety

      The head switching point will be visible on all flat panel monitors.Just set your size to slightly larger than the "just scan" mode and it will be hidden.

    • @VIDEOHEREBOB
      @VIDEOHEREBOB Před 7 lety

      There are times where it doesn't show at all. Manual tracking completely removed it. Is that because it's a higher grade tape?

    • @12voltvids
      @12voltvids  Před 7 lety

      Ok that sounds like a different problem. Sounds like your exit side guide might be slightly out of adjustment. Auto tracking maximizes signal, but if the guide is slightly off it will be probably low at the exit point that causes noise. By manually tracking you are able to bring the rf up enough at the end of the track, while slightly lowering the rest of the signal. That is why many late model machines by companies like Mitsubishi were junk, because they removed the ability to manually track the tape.

  • @tuberworksjones
    @tuberworksjones Před 8 lety

    Well I got a distinction in electronics trade, at college ,but in reality most of the stuff I try to fix ends up in the bin.

    • @12voltvids
      @12voltvids  Před 8 lety

      +Kenneth Jones Yes a lot of it does. I used to make a living fixing VCRs and TVs, but wisely got out before the industry took a nose dive.

  • @supermasterPIK
    @supermasterPIK Před 8 lety

    Do you work on Betamax 711 mechanism? I need help. Thanks.

    • @12voltvids
      @12voltvids  Před 8 lety

      Yes lots of experience on 710 and 711 mechanism.I have a broken beta (well one that I picked parts off to repair 2 others) that I could tear down to demonstrate,

    • @supermasterPIK
      @supermasterPIK Před 8 lety

      O got a 5400 (power but no tape movement) and a 5600 like new but don´t power up, even I have the remote.
      Hop your video soon.

    • @supermasterPIK
      @supermasterPIK Před 8 lety

      I also have the belt kit for 5400. I´d verry appreciate your help-

    • @short-video563
      @short-video563 Před 4 lety

      VCR tk kar do ga 8196020481

  • @dimitra.d792
    @dimitra.d792 Před 3 měsíci

    do you have someone video with nordmende vcr
    v102 ?

    • @12voltvids
      @12voltvids  Před 3 měsíci

      Never seen one. Sounds like a pal VCR. We don't see pal equipment here much.

    • @dimitra.d792
      @dimitra.d792 Před 3 měsíci

      ok has keep the cassete inside i listen a motor turn and has no eject even turns the cassete @@12voltvids

    • @dimitra.d792
      @dimitra.d792 Před 3 měsíci

      is like with the old jvc vcr you repair on your canal of that you must lift the pcb circuit if you want to see the mechanical parts

  • @faiyazuddinmohammed4705

    Sir I have Sony model slv-x7 mechanism I need images pls

  • @user-rn3gd3bo3l
    @user-rn3gd3bo3l Před 19 dny

    ישתבח שמו לעד אין על היפנים

  • @johndavis1465
    @johndavis1465 Před 9 lety +1

    This link shows a DVHS format (never heard of it)
    czcams.com/video/sgMVNKnv5z0/video.html
    regards
    john

  • @donald1056
    @donald1056 Před 8 lety

    You never use cordless tools do you!!! No big deal!!

    • @12voltvids
      @12voltvids  Před 8 lety

      +Donald Ellett
      Bahaha, I have to get some excercise!

    • @donald1056
      @donald1056 Před 8 lety

      Understood