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This is the first Archived Forum which was active between 17th April 2007 and 1st March February 2012

 

Latest post 07-20-2009 10:45 AM by Dillen. 7 replies.
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  • 06-24-2009 8:35 AM

    Strange behavior Beomaster 1900-2

    I've got this Beomaster 1900-2 for many years. It was given me by my granddad and it worked fine for over 15 years, until now it started behaving strangely. The volume suddenly goes louder and a minute later is goes down again. The volume control light goes out when the volume goes up, and turns back on when the volume goes down again.


    Some of the light bulbs are burned out. Does this have anything to do with the volume control?
    How can I fix this?


    Thanks

  • 06-24-2009 11:30 AM In reply to

    Re: Strange behavior Beomaster 1900-2

    Hello and welcome to Beoworld!

    I think the burned out bulbs may well be affecting the way the unit operates. Your best chance of sourcing a replacement would be to send a pm to Martin (username Dillen) on this forum.

     

    Simon

  • 06-24-2009 2:13 PM In reply to

    • lausvi
    • Top 150 Contributor
    • Joined on 04-16-2007
    • Helsinki - Finland
    • Posts 498
    • Gold Member

    Re: Strange behavior Beomaster 1900-2

    I can't rate Martin's lamp-kits high enough, I have just one for the 1900 waiting a moment to replace the lamps. And I have already repaired many 1900s by Martin's kits. Great kit and the instructions are very good.

    The volume troubles are almost surely related to the volume meter lamps; the fact that they go on and off could mean the filament of the lamp is broken but still in contact and as it heats up / colds down it contacts and breaks contact. I have seen some light bulbs doing that just before they burn out completely. Or there might be some loose contact in the volume controller etc. but better to wait for a more precise info from Martin. Yes -  thumbs up

     

    Bang & Olufsen - The art of controlling sound, picture and light

  • 06-25-2009 2:53 AM In reply to

    • Andrew
    • Not Ranked
      Male
    • Joined on 03-16-2009
    • Melbourne, Australia
    • Posts 49
    • Bronze Member

    Re: Strange behavior Beomaster 1900-2

    I believe the volume in the Beomaster 1900 is controlled by photo sensors ie light sensors which sit inside the light boxes where your volume display lights are located.

    When your bulb goes out - ie stops working, the Beomaster is reacting to the change in light as if you had manually adjusted the volume. Indeed the volume controls on the BM1900 effectivly only control the lights in the two light boxes and it is the brightness and balance of these lights which in turn control the volume.

    Replacing the faulty bulb should resolve your problem.

    Andrew

  • 06-25-2009 8:22 AM In reply to

    • Dillen
    • Top 10 Contributor
    • Joined on 02-14-2007
    • Copenhagen / Denmark
    • Posts 5,008
    • Founder

    Re: Strange behavior Beomaster 1900-2

    It is correct that the volume control is optical with a miniature bulb and LDR resistors sitting inside a
    sealed housing on the main board.
    There's one housing, one lamp and 4 LDR resistors. Two LDR's handle the volume, the other two handles loudness.
    (Balance control is a sliding potentiometer under the large aluminum lid.)
    If the bulb inside the housing burns, a safety circuit cuts in and the Beomaster will mute completely.
    If you have sound from the Beomaster, we can rule out this lamp.

    The panel lamps, however, is a different story. And they are in fact real lamps, not LED's or LED displays as some people think.
    The only LED is the red standby indicator.
    The volume indicator "arrows" on the panel are not directly related to the volume circuit but merely indicates the setting.
    It's quite common to see strange behavior if one or more front panel lamps are burned and/or are of a wrong wattage, even
    the lamps for checking the bass, treble and balance controls are important to give the right load and power supply discharge
    effect when going into standby.
    Some Beomasters will play fine but won't be put into standby without pulling the mains plug, others
    will change channels intermittently or continously, others again will do other things.
    Generally, the lamps are quite critical for correct operation in these wonderful machines.

    I can supply a kit containing a complete set of fresh lamps of correct wattage (plus a spare).
    The kit comes with (dis-)assembly instructions and will fit Beomaster 1900 / 1900-2 / 2300 / 2400 /2400-2
    Soldering and basic electronic skills and tools are required to replace the lamps.

    Martin

  • 06-25-2009 9:47 AM In reply to

    Re: Strange behavior Beomaster 1900-2

    Thank you all for your quick answers. This was very helpful.

    I going to replace those light bulbs.

  • 07-20-2009 6:59 AM In reply to

    Re: Strange behavior Beomaster 1900-2

    I'm very pleased to say, I've replaced the lichtbulbs and the Beomaster is working great again.

    Smile

  • 07-20-2009 10:45 AM In reply to

    • Dillen
    • Top 10 Contributor
    • Joined on 02-14-2007
    • Copenhagen / Denmark
    • Posts 5,008
    • Founder

    Re: Strange behavior Beomaster 1900-2

    Good job !  Yes -  thumbs up

    Martin

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