Home Forums Product Discussion & Questions BeoCord Beocord 8004. Playback only short time..

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  • #47269
    jbh2
    BRONZE Member

      Hi all.

      Got new belts, good cleaning and new LEDs in display.  Very small LEDs.
      When playback it only play for approx.  1 sek,  then no sound at all in both channels.
      Then REWIND for 3-4 seconds and then it can play again but only 1 sek.

      Tried other tapes, same result.

      Record is OK.

      Any hints  ?

      Br  Jens

      #47270
      Dillen
      Moderator

        A capacitor problem, perhaps.
        Check the 7Vref to the Dolby ICs.
        Does the VUs still deflect or will they fall to zero as sound disappears?

        Martin

        #47271
        jbh2
        BRONZE Member

          Hi Martin.

          I will check the 7v ref.   But  Dolby is OFF.
          Yes the VU  follow the sound.

          If I gently touch the pins on tapehead, L and R, with my screwdriver I get 50 Hz hum i both.
          Very clear, steady and strong signal.    No dropout in hum.

          #47272
          Dillen
          Moderator

            Sounds like a mechanical problem, – misaligned tapeheads or something bent in the tape path.
            Is the tape running off the head?

            Martin

            #47273
            jbh2
            BRONZE Member

              The Recording is OK.  Only one head.   Tape is running perfect on head.   Only Playback problem..

              #47274
              Dillen
              Moderator

                Did you check the 7Vref?
                It’s not important if Dolby is in or out. The signal runs through parts of the Dolby ICs regardless.

                Martin

                #47275
                jbh2
                BRONZE Member

                  No time yet, but will do it soon.  Thanks again for fine info,

                  #47276
                  jbh2
                  BRONZE Member

                    Result of checking the 7 volt.     Both L and R were 6,89 Volt and the 14 volt is 13,8 Volt.

                    So I think thats fine.   But again, with 50 hz hum on the tapehead,  I get fine signal in both channels as long as I will.
                    Is it possible to connect a sinus signal from a tonegenerator at the tapehead.  (input on playback amplifier)

                    Or do you have any other suggestions I would be happy  ?

                    Thanks again Martin.

                     

                    #47277
                    Dillen
                    Moderator

                      So…

                      Sound drops out after a few seconds, and VU-meters follow?
                      The tape keeps running?
                      Both tape reels are rotating?
                      And if you touch the tapehead solder tags you get a buzz from the speakers and deflection on the VU-meter?

                      Sure the tape has a good recording on it?

                      Martin

                      #47278
                      jbh2
                      BRONZE Member

                        yes to all.
                        I will try to find another tape, and also have another tapedeck (working) and will make a  new recording on that.

                        Will a bad/very old tape have that performance,  sounds OK a short time, then silence.  ?

                        #47279
                        jbh2
                        BRONZE Member

                          Finally, its a winner, thanks to you Martin.

                          I got the HK2500 tapedeck up and running.  Just new belts then OK.  Then I tried my testtape in it,  and the tape was full of dropouts, and very bad overall.
                          Then tested a lot of my old tapes and most of them had dropouts.
                          (Old tapes loose their megnetism)
                          But found 2 good ones (99 % good)   and gave them to B&O 8004.
                          Holy moses,  it worked.  !      Both channels, VU, dolby in/out,  timerdisplay.  All fine.

                          (until now, maybe some details isnt working, but so far so good)

                          So you were right Martin and I was getting “blind” and forgot the testtape,  and only focused on the 8004.
                          Thanks for keeping your interest and continued help.  Very grateful and happy.

                           

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