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DENON DCD-890 service manual?

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    #21
    Re: DENON DCD-890 service manual?

    I am little bit lost in translation :-)

    - What's an upside down test?
    - How you notice the motor might have problems?

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      #22
      Re: DENON DCD-890 service manual?

      Originally posted by Francesc V. View Post
      I am little bit lost in translation :-)

      - What's an upside down test?
      - How you notice the motor might have problems?
      This

      Originally posted by stj View Post
      turn the player upside-down before you play the tracks - see if it fixes it
      Usually they are little bit louder than normal, and you can test bushing play by hand.

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        #23
        Re: DENON DCD-890 service manual?

        upside-down test.
        put in the disk and flip the player over onto it's top
        if it works the player has a worn or sticking frame or head assembly.
        the test works because your taking the weight off of the mechanism.

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          #24
          Re: DENON DCD-890 service manual?

          I am start thinking that maybe it's a mechanical problem.......just a guess
          The original CD's that is reading, they jump in the same place all the time

          As an example from one CD: on track 2, on track 7, 18 & 20
          Rest of the time and tracks it reads and sound perfect.....

          In case I would like to buy the mechanism. Where could I find it? So far I haven't found it on aliexpress

          Here you have it.
          Attached Files

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            #25
            Re: DENON DCD-890 service manual?

            Originally posted by Francesc V. View Post
            I am start thinking that maybe it's a mechanical problem.......just a guess
            The original CD's that is reading, they jump in the same place all the time

            As an example from one CD: on track 2, on track 7, 18 & 20
            Rest of the time and tracks it reads and sound perfect.....
            Check plastic sledge and other side of that gear for cracks, and of course clean and lube metallic rod on which laser travels.
            Attached Files

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              #26
              Re: DENON DCD-890 service manual?

              Thanks!! Do "they" sell replacements for these parts?

              P.S: I've ordered a second hand mechanism from Ebay......fingers crossed. Let's see if there is any difference.

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                #27
                Re: DENON DCD-890 service manual?

                No, only whole mech if you are lucky. And even then it most likely will be chinese knockoff.

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                  #28
                  Re: DENON DCD-890 service manual?

                  From the time being I have the certainty that the CD mechanism works perfect. I have exchanged it with other Cd reader that uses same conexions and both works perfect. So I know for sure that is something wrong in the DENON PCB.

                  I am able to read the CD info (TOC read), but not playing it. It tries it but maybe it has not the right power.......

                  Any idea suggestion where to start from?
                  Attached Files
                  Last edited by Francesc V.; 04-10-2023, 12:03 PM.

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                    #29
                    Re: DENON DCD-890 service manual?

                    Indeed it was related with power (amplifier transistors)*.


                    - I replaced CXA1372S and 2 operational amplifiers (IC105 and IC106). Same result........reading TOC and some intermittent reading in original CDs (jumpy sound).

                    - I realised that R185 was reading about 33k instead of 100k, so I've replaced C168 (75pf) (they are connected in parallel)........then resistance reading went back to normal.

                    - I replaced TR116,TR118 (BC369 PNP) with S8550. They are not pinout compatible, but I managed it.

                    - I've replaced TR117 (BC368 NPN) with S8050. Again changing from ECB configuration to EBC.

                    The 3 transistors were "ok" but with a lot of HFE difference........so the new ones have a really closer HFE.

                    BC369 (1 & 2)
                    Hfe 183 & 260
                    Ie - 6.4mA & 6.4mA
                    Ube - 621mA & 608mA

                    BC368
                    Hfe 27
                    Ie - 6.2mA
                    Ube - 614mA
                    ICEO - 13mA
                    ICEs - .54mA


                    The CD player is back to life.
                    * If you look closer at the PCB behind the color is more "brown"......some burnt there.

                    Perseverance and countless hours measuring like a monkey without any knowledge.
                    However if I look it into perspective, I should have paid more attention to that burn section from the very beginning.
                    Attached Files

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