Denon DRM-700 Tape Cassette Deck

Discussion in 'The Projects Forum' started by tom66, Dec 5, 2011.

  1. tom66

    Thread Starter Senior Member

    May 9, 2009
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    I'll admit it - I'm a dumpster diver!

    I found this very nice looking Denon DRM-700 in the skip. I took it home with me. It looks pretty good, but has some scratches on the case. The power cord had been chopped.

    I wired in a temporary power cord and to my surprise, it powered right up! The VFD lit up nice and bright and displayed a VU meter, "00:00" and a few other things. The unit makes a soft hum as it seems a motor is always spinning(?)

    Then I found a blank cassette, inserted it into the deck, pressed play and it wouldn't move the spindle but did make a loud whirring sound. I tapped it a few times and it started moving. It seems temperamental to get started, but otherwise works fine.

    I did eventually find an audio cassette with something recorded on it. (I don't even have CDs here - everything is digitised.) The VU meters on it did react to the tape. Unfortunately, no amplifier yet, so can't test that, but I suspect that will be fine.

    Any idea on why the deck might slip occasionally? I've been warned about the belt slipping - could this be the problem?
     
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    The rubber drive belts dry out with age and then they slip. Belts are readily available on line. They can be a pain to replace.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I've never worked on a Denon deck.

    Besides the belt, you can wind up with dried-out rubber rollers at the capstan. When they get dried out, they just won't pinch the tape to provide a smooth pull.

    Make sure the take-up is working for both sides. If it's not keeping up near the ends of the tape, you can wind up with a birds' nest. They'll almost always work OK when the takeup reel is nearly empty; but as they fill with tape, they lose mechanical advantage to the point where the clutch and/or belt may start slipping.

    You may not remember this, but tape heads get magnetized, and need to be demagnetized periodically. I used to demagnetize my cassette deck about every 50 hours worth of play time.

    Examine the head very carefully to see if it has excessive wear or has scratches. If the head is in poor shape, it'll ruin your tapes.
     
  4. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    Another thing that fails in the drives of old cassettes: the "friction paddles" that apply slight drag on the "undriven" reel to keep the tape tight during playback. Those wore out on my old Nackamichi and gradually the sound lost high frequency at the beginning parts of every tape because the tape did not stay taught to the head. Bummer.
     
  5. tom66

    Thread Starter Senior Member

    May 9, 2009
    2,613
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    Okay, thanks for everyone's input. I'll have a look at the deck later.

    The eject mechanism seems a little loose, but still works.

    Also, it's been through the public education system :\ so it's got loads of ugly scratches on the case. Any idea how to remove these?

    Otherwise it's in good condition, can't see why someone would throw it out. It's a bit temperamental to start, but nothing too serious. I played a test tape for 30 minutes and there was no sign of it eating tape, which is good.
     
  6. sheldons

    Active Member

    Oct 26, 2011
    616
    101
    here is the service manual for that model
     
    Loredana likes this.
  7. tom66

    Thread Starter Senior Member

    May 9, 2009
    2,613
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    Thanks for that. I'm going to give this unit a good clean and service and see what to do with it.
     
  8. Loredana

    New Member

    Nov 10, 2014
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    I have a problem, putting the door spring. I don't remember in wich way. Somebody can help me? I downloded the Service manual ,but there isn't this information.Thanks
     
  9. sheldons

    Active Member

    Oct 26, 2011
    616
    101
    Post a photo and let's have a look. ....shouldn't be too hard. ...
     
  10. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,785
    945
    Q-tips and WD40 will do a good job of cleaning the capstan rubber roller. Expect to use several dozen to get it clean. remove any excess WD40 with isopropal alcohol but dont soak the rubber. alcohol is bad for it.
     
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