Denon DN-790R Belt Replacement and Capstan Motor Troubleshoot - Speed/ Wow & Flutter Instability

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  • Опубліковано 13 гру 2024

КОМЕНТАРІ • 78

  • @samoworks4648
    @samoworks4648 2 місяці тому +1

    Hi Peter. I recently got into restoration of cassette decks, most of the videos on UA-cam are all "introductory level" like changing belts and pinch rollers, lubricating.... etc.
    I was dying to find more "technical" way of restoration for weeks, and today I finally stumbled upon your channel.
    All I can say is your channel is a serious TREASURE TROVE for people like me who's into all the nitty-gritty of restoring a cassette deck to perfection. I really appreciate you for sharing all your expert knowledge and techniques!
    I was more of a "college and electronics boy" and never touched things like a lathe or mill before, but this new hobby of cassette deck restoration pushed me to purchase a mini tabletop lathe. I'm just starting my journey and I sure hope one day I could be as good as you are.

    • @asbcustom
      @asbcustom  2 місяці тому +1

      Thank you for your kind words, and congratulations on your new mini-lathe!
      If I may, I'd like to recommend a series of books I think you might enjoy. Firstly, the "Workshop Practice Series", by various authors, and to go along with it, "Fundamentals Of Dimensional Metrology" by Ted Busch. This one will help you avoid all the pitfalls of the inevitable wives tales and superstitions inherent in the discipline.
      Best of luck on your new endeavor!

    • @samoworks4648
      @samoworks4648 2 місяці тому

      @@asbcustom Thank you so, so much for the reply and recommendation of study materials. I would definitely read them.
      In the mean time, I hope you won't mind I make some inquiry about the essential measurement tools for cassette deck restoration.
      I've already purchased a digital micrometer as a starter, and I see in your video that you are using lever type DTI gauge a lot to check for concentricity. (I hope I'm getting the tool's name correctly.)
      I guess it will be the next tool I should purchase?

    • @asbcustom
      @asbcustom  2 місяці тому

      @@samoworks4648 Really, the next tool would be at least one of the lathe operation books in the series. That will help you to understand better what is needed for the operations you wish to perform. They have quite a few, I read the Myford one about 40 years ago and found it invaluable. It may have been this one: www.amazon.com/Basic-Lathework-Workshop-Practice-Stan/dp/1854862618/ref=sr_1_fkmr0_1?crid=2FQ395G56LSAF&dib=eyJ2IjoiMSJ9.41uLcpV9Roh_E6cpPKZEtd8PxMOxCx-3OcddPdL_Lf18NwTrrVFP-EUUsd0f7T3B.s4Sej4VdLQ0u_z4bMxs7lGCSWrH7Ty0Hk-BjK6BaXJA&dib_tag=se&keywords=workshop+practice+series+myford&qid=1727633230&s=books&sprefix=workshop+practice+series+myford%2Cstripbooks%2C151&sr=1-1-fkmr0

  • @JamesE707
    @JamesE707 Рік тому +2

    Great idea at @22:00! especially for getting the brushes over and back on to the commutator without disturbing them.

    • @asbcustom
      @asbcustom  Рік тому +2

      Ah yes, thank you, that's why they put those slots in there.

    • @JamesE707
      @JamesE707 Рік тому

      @@asbcustom Of course stupid me reassembled similar motors a different way - by first engaging the brushes with the commutator, then using a convex ended guide rod to steady the shaft as I place the permanent magnet part into place. Next time I may do it the proper way! :)

  • @SDsailor7
    @SDsailor7 2 роки тому +2

    I read on one of the electronics forums that my problem is due to the transport belt being loose I recently bought my Denon DN-790r and it worked good for about a couple of days and then the problem started so i will replace both belts and clean and lube anything that needs it. I don't have the specialized tools like you have but i will make do with what i have.
    Your video has been very helpful.

  • @tushar8133
    @tushar8133 Рік тому

    Indeed a very detailed video. Found this in my UA-cam feed after several weeks of searching for tape mechanism with closed loop and three discrete heads.

    • @asbcustom
      @asbcustom  Рік тому

      Thank you so much for watching and commenting!

    • @asbcustom
      @asbcustom  9 місяців тому

      Robimy to, żeby ci, którzy mają uszy, usłyszeli :)@@tomaszkluska6419

    • @tomaszkluska6419
      @tomaszkluska6419 9 місяців тому

      @@asbcustom Na pewno nie dla pieniędzy :)
      Pozdrawiam gorąco i dzięki za fantastyczny film!

    • @asbcustom
      @asbcustom  9 місяців тому

      @@tomaszkluska6419 Bardzo dziękuję!

  • @chef223399
    @chef223399 6 місяців тому

    Thank you. I was so frustrated with those two belts.

    • @asbcustom
      @asbcustom  6 місяців тому

      You're very welcome, glad I could help.

    • @chef223399
      @chef223399 6 місяців тому

      @@asbcustom I can't find your ebay sales and I also have a Denon DRS-810 that I may want you to service. I didn't see any cassete player links on the website, can you help?

    • @asbcustom
      @asbcustom  6 місяців тому

      @@chef223399 You may use the contact link on my Website to send a message, it comes to me directly. Thank you.

  • @Sergey-vj8iv
    @Sergey-vj8iv 2 роки тому

    Просмотр принёс массу удовольствия. Благодарю вас.

    • @asbcustom
      @asbcustom  2 роки тому +1

      Спасибо за просмотр!

  • @lewismcphersonTXus
    @lewismcphersonTXus 2 роки тому +1

    Ok partner, your video was very good, because I have the DRW-840 and DRM-800A and I was trying to find the same variation. So thank you very much.

  • @JamesE707
    @JamesE707 Рік тому

    While doing similar work to yours, I observed tape flow for when (a) only the take up pinch is engaged, and (b) only the supply pinch roller is engaged. Listening in to a recording of white noise (one's own white noise reference tape as an example) I checked for any 'wobbling' of the azimuth. But if it's not quite steady in this scenario, but is fine when both capstans are engaged, then I guess it's not bad.

    • @asbcustom
      @asbcustom  Рік тому +1

      Interesting, I've tried removing the supply, but never the take up roller.

  • @asbcustom
    @asbcustom  9 місяців тому

    Sorry @tomaszkluska6419, I inadvertently deleted your comment. My reply was: Robimy to, żeby ci, którzy mają uszy, usłyszeli :)​

  • @verastaki
    @verastaki 2 роки тому

    I enjoy fixing Compact Cassette Tape Mechanisms. I fixed dozens of them. Most common one is the Tanishan based Mechanism that's easiest to fix, since it's one of most simple mech's. There are times when it will get very stressing, especially fixing quality, Full-Logic Selinoid Driven, Computer-Controlled Mechanisms with tiny springs and details you need to watch out for.

    • @asbcustom
      @asbcustom  2 роки тому +1

      Thanks Verastaki for your comment, I'd love to see some of your repairs, have you thought of making a video?

  • @nohrtillman8734
    @nohrtillman8734 Рік тому

    At 32:17 onwards, is the free run, no load, 12V speed of these known? Near as I can tell no one has found actual specs on the MMI-6H2’s, and I’ve not seen any images where it’s ever advertised on the motor itself.
    I ask because applying 12.05V, with no control lines (A or blank) connected, and no mechanism I recorded 6295 RPM using a contact tachometer.

    • @asbcustom
      @asbcustom  Рік тому +1

      I have clocked a motor at 6000+ RPM but I can't recall which one it was. I'm pretty confident that it was a control motor but don't know from which deck.

  • @keithjones7810
    @keithjones7810 2 роки тому

    Got two Denon decks. DR M34HR and DR M10HX. I use the 34 for recording and the 10 for playback. Not expensive decks but they perform so well. Loved the video. Good Luck.

    • @asbcustom
      @asbcustom  2 роки тому

      Thank you for watching and commenting!

    • @Bound2glory
      @Bound2glory 11 місяців тому

      ​@@asbcustom wondering - do you offer service/repair on cassette decks?

    • @asbcustom
      @asbcustom  11 місяців тому

      @@Bound2glory Thank you for watching, and yes I do. Please contact me from link on the About page here: www.youtube.com/@asbcustom/about

    • @Bound2glory
      @Bound2glory 11 місяців тому

      @@asbcustom nothing is coming up in the link?

    • @asbcustom
      @asbcustom  11 місяців тому +1

      @@Bound2glory There should be a button to reveal the e-mail address, they do this to prevent us from getting spammed. If it doesn't show, then please use my business e-mail at: www.asbcustom.com/contact.html. Thanks.

  • @Johny666EU
    @Johny666EU 2 роки тому +1

    nice one, i can tell you a tip for the motors. instead of metal wire pins use capacitor with thick legs, put into clamp and put on top of it back of the motor and will be easy to asembly motor into brushes. im using panasonic 4700uf 35v. is big anouth. for cleaning brushed im using cotton buds with IPA and i just simply rotating between them and in most of the cases is good.

    • @asbcustom
      @asbcustom  2 роки тому

      Thanks for the tip and for watching!

  • @SDsailor7
    @SDsailor7 2 роки тому +1

    Thank you for the video it was very detailed and informative. and the video quality was very good and you spoke clearly so we could understand. Excellent video!
    Cheers

    • @asbcustom
      @asbcustom  2 роки тому

      Rob, thank you for your comments, I really appreciate it.

  • @JamesE707
    @JamesE707 Рік тому

    Thanks you, I’ve not seen this before.
    Regarding tape flow: good shell too, the guides either side appear to be fairly steady. I wonder if the Denon would allow for variable pinch roller guide height setting? This old Sony I’ve been working on, does allow this.
    Nice work on that motor.

    • @asbcustom
      @asbcustom  Рік тому

      As I recall, the supply side is adjusted to match the head guide, the take up side has no built in adjustment, but in a shop like mine, that's no deterrent at all if I need to correct something.

  • @stivkrunic8612
    @stivkrunic8612 2 роки тому +1

    Maybe is tape path issue ; or bended capstan axel { rarely } ; many times good looking pinch rollers aren't good ???

  • @JamesE707
    @JamesE707 Рік тому

    I realise that this video is now a bit dated, but some thoughts ..
    Speed variations perplex me sometimes, assuming your work on the brush/commutator was effective, I guess I'd be looking at that motor controller. It could be based on the AN6651/AN6652 series or similar which was designed around a wheatstone bridge principle. Also might have been prudent to replace any transistors in there and caps. One more thing, may be look at the back tension too - did it fluctuate?; this can't be seen or even sensed by hand. I cured a very weird rising wow/flutter issue with a single capstan Sony (TC-206SD) by *eventually* disengaging the back tension! The back tension pad (although visually clean) was offering a varying coefficient of friction, an idler tyre had left its deposite behind and the pad just mopped it up, all macroscopically of course.
    I'll stop bleating on now, promise! :)👍

    • @asbcustom
      @asbcustom  Рік тому +1

      That was my thought also, I changed that IC out and it made no difference. Finally located a NOS motor and it snapped back into spec. On another similar motor, I went through the same process and even a new motor didn't do the trick. It turns out I neglected to check the pinch roller pressure and it was way out on the high side. Bringing it into spec., also brought the flutter into spec. I do always check it as a matter of routine but forgot on this one. I find most of the issues on these decks are mechanical, not electronic.
      Bleat away at your pleasure.

    • @JamesE707
      @JamesE707 Рік тому +1

      @@asbcustom The permutations of the things that can go slightly awry are so high, small wonder we sometimes seem to chase our tails! Glad you sorted it.

  • @CRH1A-1145
    @CRH1A-1145 10 місяців тому

    It's quite a wonder to me that the deck comes with 3 motors rather than just one. Apart from the capstan motor, what do the other two motors do?

    • @asbcustom
      @asbcustom  10 місяців тому

      Thanks for watching.
      One is for the reels, the other controls the head stack. The separate motors are a much better design.

    • @CRH1A-1145
      @CRH1A-1145 10 місяців тому

      @@asbcustom Really interesting. (1) I believe the reel motor is certainly on for FFW / REW modes? (2) In playback mode - is the reel motor activated too, along with the capstan motor? Or is it just capstan doing everything? (3) I don't quite understand here - is the head stack motor in charge of turning the head + auto-reverse, or lifting the head for playback? (4) Which motor does the auto-stop function?

    • @asbcustom
      @asbcustom  10 місяців тому

      Yes, the take-up reel is active during play mode. No auto-reverse on this deck, but yes, the control motor elevates the head stack. Auto-stop isn't controlled by a motor in that way, the motors are controlled by the auto-stop function.

    • @CRH1A-1145
      @CRH1A-1145 10 місяців тому

      @@asbcustom Ah, and under play mode, will the reel *motor* spin at a reduced speed compared to FFW mode; or would it instead spin at full speed, leaving the capstan / pinch roller and tape to help slow the take-up reel down?

    • @asbcustom
      @asbcustom  10 місяців тому +1

      The take-up reel spins faster than the capstan, but at much lower torque. The capstan controls the tape speed, the take-up reel packs the tape.

  • @biblequestionsanswered6572
    @biblequestionsanswered6572 2 роки тому

    Hi, I have a Phase Linear 7000 cassette player. The reel drive motor fails and stops once in a while, can it be serviced or what can I do to fix it ? Thanks ASB Custom...

    • @asbcustom
      @asbcustom  2 роки тому +1

      I have no experience with that model but it could possibly be a bad connection or maybe a dead spot in the motor. Thanks for watching.

    • @biblequestionsanswered6572
      @biblequestionsanswered6572 2 роки тому

      @@asbcustom I found a used motor on Ebay and it fixed the problem. I also replaced the pinch rollers with new ones. Thanks for your feed back, Lord bless you and your family !

    • @asbcustom
      @asbcustom  2 роки тому

      @@biblequestionsanswered6572 Well done, glad you got it up and running, and the same to you and yours!

  • @SDsailor7
    @SDsailor7 2 роки тому

    is the small belt on that motor for the heads? to make the transport go up and down?
    My transport keeps going up and down continuosly and the tape does not travel.
    Thank you

    • @asbcustom
      @asbcustom  2 роки тому +1

      Yes, there is a smaller square control belt that also needs to be changed, these are normal maintenance items as they degrade over time. I hope this solves your problem, these are great decks!

    • @SDsailor7
      @SDsailor7 2 роки тому

      @@asbcustom Well, I removed the transport mechanism and inspected for broken gears or gear teeth and found nothing all the gears looked good.
      I cleaned the flywheels and the shafts and lubed the shafts also cleaned the large belt and it is still good. I also removed the pinch rollers and cleaned them, the left pinch roller "cradle" was a little tight so i loosened it.
      I reassembled everything and tested it, I still have the same problem.
      I fast forward the tape and that seems to help because the tape started playing but if i start the tape from the begging the head block starts cycling like before. So i am thinking that it is an electrical problem.
      The arms at the left are those to detect the type of tape that is playing?
      What are your thoughts?
      Thank you

    • @asbcustom
      @asbcustom  2 роки тому

      @Rob Hernandez Assuming that you changed the belt and it has the correct tension, then from what you describe it may be the cam switches. I posted an image here; postimg.cc/xJTfQp1T
      These are very delicate and as far as I know, irreplaceable.
      Additionally, when you say that you loosened the left pinch roller cradle, if you backed out that nut with the green paint on it in order to remove or "loosen" it, it must be set back up with a particular gauge. That nut sets the left tape guide height and will run skewed if incorrect.

    • @SDsailor7
      @SDsailor7 2 роки тому +1

      @@asbcustom I did change the small belt with a new one but I don't know if it is the correct tension. I can see the motor and belt moving now I put a mark on the white pulley and I can see it moves everytime the head block activates and deactivates.
      The cradle was scraping on the inner side of pinch roller cradle against the backplate so I had to loosen it just enough to clear.
      The tape played fine.
      I will check those finger switches.
      Thank you

    • @SDsailor7
      @SDsailor7 2 роки тому

      @@asbcustom If I remove the board will anything fall out of place? Or are the switches secure?

  • @samankumara7461
    @samankumara7461 Рік тому

    Great job Sir 👍

  • @savneetsinghrairai6823
    @savneetsinghrairai6823 2 роки тому

    Most of cassettes deck i throw out just for not getting part earlier i threw cassets almost 15 years ago to empty space ....now they look kind of cool i kept two of them ...how music player was back then

  • @bob-s-bit-s
    @bob-s-bit-s 2 місяці тому

    hi know the leader tape they sell it at tape line on big spools i use it like you i moved alot of it on to the basf 1/8 reels
    i have alot of studio 1/8 tape dubbing gear
    there is cassette decks that just a right pain to get right why i went over to alot of pro gear love audio liner on betacam sp decks
    i was repairing some decks WOW they walk over cassette's big time the tascam da 238 is ace 3 3/4 ips

  • @MMSound-zl4eo
    @MMSound-zl4eo Рік тому

    НИКАКОЙ РАЗНИЦЫ.