in Search
Untitled Page

ARCHIVED FORUM -- April 2007 to March 2012
READ ONLY FORUM

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

 

Latest post 09-18-2009 3:22 AM by Dillen. 1 replies.
Page 1 of 1 (2 items)
Sort Posts: Previous Next
  • 09-17-2009 7:32 PM

    • Howzit
    • Not Ranked
    • Joined on 08-25-2009
    • Posts 7
    • Bronze Member

    Beomaster 4400, Just acquired, cleaning sliding contacts?

    Hey again,

     

    I just got a hold of a Beomaster 4400 on eBay. It seems to function nicely.

    Couple of problems I found. The first, is that the stereo light doesn't work when im playing through any of the Tape inputs. The manual says the stereo light is an FM stereo light, so im assuming if a I connect an antenna and use FM the stereo light will work?

    I noticed with my Beomaster 4000, that the frequency tuning lights didn't work until I connected an antenna. So im guessing the stereo light only works with FM and not the rest of the input modes? (Tape1, Tape 2 Phono e.t.c)

     

    The second thing was that the sliders make a scratchy feedback noise through the speakers. The volume slider makes so much scratchy noise that it actually fiddles with the channel output, the one speakers actually cuts out completely, and if I give the volume a gentle tap, it reconnects.

    Its not a big deal if Im not playing around with the controls too much I guess.

    I did do a search and found some posts that mentioned that the sliders do tend to get scratchy and may need a cleaning.

     

    So, without being an electronics expert of any sort, well, at all, how can I clean them. From my search it seems I need contact cleaner. How do I get the slider off though?

    Do I need to open up the whole unit? Are there numerous screws that hold the sliders in place? Is it a "snap-on" type of fixture? I dont want to snap and break something by accident having not seen a hidden screw thinking its a "pop-off" style thing.

     

    Any detailed info on how to get the sliders on and off would be appreciated.

    By the way, I have a second Beomaster 4400 I got from eBay, but a lot of the buttons are damaged, the unit doesn't work, but cosmetically, its good, and seemed to have been cared for better. The sliders a newer and the few buttons that do work snap with a crisp click. I got it assuming I can harvest parts from it for the functioning unit, do a "restore" of sort.Any advice and suggestions appreciated.

    Filed under:
  • 09-18-2009 3:22 AM In reply to

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

    Re: Beomaster 4400, Just acquired, cleaning sliding contacts?

    You will have to dismount the sliders and take them apart.
    Contact cleaner will not remove anything, only shift the dirt around and in the best
    of cases it won't add to the mess.
    The scratching sounds are usually not due to contaminatino of the resistive track inside the
    potentiometer but oxidation on the metal track next to it and spraying something in there won't
    provide a lasting solution.
    The oxidation will have to be removed mechnically. I like to use a glasshair brush for this
    followed by contact cleaner and cotton buds to wipe it all dry. Dry and clean is good.
    Some people like to add silicone grease to the tracks but my experience is that it will only catch
    dust and dirt that would otherwise not stay.

    The sliders are not easily accessed. If you haven't got experience in servicing B&O, which
    is evident since you don't know how to get the sliders out, I suggest you leave the job to
    someone who has. It shouldn't be a costly repair and the Beomaster is easily worth it.

    And you are right about the stereo light. Maybe the lamp is defective.

    Martin

Page 1 of 1 (2 items)