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BELL & HOWELL 652 SOUND PROBLEM

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  • BELL & HOWELL 652 SOUND PROBLEM

    I have a 652 Filmosound, but it is totally silent with no hissing or sound from the speaker. All the tubes seem to glow, the fuses are ok and the exciter lamp lights up after a few seconds...any suggestions? Thank you

  • #2
    The only ting I could suggest is to try plugging in an extension speaker to check if the built in one isn't working due to damage or if the socket (which should mute it if an extension one is plugged in) has corroded or been damaged cutting off connection to the main one.

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    • #3
      Justin, try these in turn, don't forget that this model could be 58 years old as it was introduced in 1965.

      1) The external loudspeaker socket at the front of the projector has three pins. Metal one at 9 o'clock, a further metal one at three o'clock. These two are connections to the external speaker. However, there is also a further large (plastic?) pin at 12 o'clock which cuts out the internal speaker. Power up the projector and switch on the amp. Wait for a minute or so (for the amp to warm up) and then by using a matchstick, "wobble" the large pin at the 12 o'clock position. This may get the internal speaker working

      2) Disconnect from mains. Using two thin metal objects, (paper clips), apply a small voltage from a torch battery. If the speaker is OK there will be an audible CLICK when doing so.

      3) Take off the back and look at the wired connections at the speaker, Check to see if secure.

      4) Still with the mains off, turn the projector on its side and remove, or slide, the bottom panel. Look at the resistors and capacitors. Are any of the former burnt out, or have the capacitors leaked. Check all soldered joints, at its age there may be some dry joints.

      5) Remove each valve, in turn, so as to not get them confused. Look at the socket. Are all the receptacles OK, do they look if the will hold the valve pins securely. Now examine the valve pins, are they nice and clean. If not, give a gentle clean with some wet and dry, but be careful not to break off any of the fragile pins. Check each valve and its holder in turn.

      6) You said above that the heaters all light up.

      7) Refit the bottom panel, Connect mains lead and test.

      8) Good luck.

      9) If the amp is still not working you will need professional help.

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