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

 

Latest post 04-07-2008 5:20 PM by Dillen. 2 replies.
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  • 04-06-2008 7:37 PM

    Seemingly dead Beogram 8000

    I have a Beogram 8000 that seems to be nearly dead. When I first received it, after plugging it in all it would do is flash the sensor arm light and a couple of segments on the display about once every 4 seconds. I've taken it apart at this point, and have it scattered about the workbench. When powering it up in this configuration, I can read exactly +5V at the output of the 7805 with no AC component according to my DMM (I don't have my scope with me at the moment). Sometimes though, the light on the sensor arm will come on, and I will read +15V at the collector of OTR1, which tells me that the CPU is turning everything on via pin 38 of IC1 (I think). This seems dependent on how I have certain things oriented with regards to the ribbon cables.

    Any idea what to check next? Where do I get this acclaimed cap kit, and how much is that with shipping to the US?

    Also, I'm really not satisfied with the cables that go from the CPU to the main circuit board. It doesn't strike me as a particularly good design electrically, and I am highly considering replacing the two 10-pin cables with something more appropriate, such as a 40-pin IDE cable. If I use every other wire, the spacing looks like it should work perfectly. I would unsolder the connector on the main circuit board, and the existing cable from the CPU can. I would then take an IDE cable with a male connector on one end, and a female on the other, cut it in half and to the right length, and strip and solder the connector-less ends to the main board and the CPU board so that I am left with a 40-pin connector. This seems like it might eliminate any possible bad connection issues. I will also go over the rest of the board for bad solder joints/traces. Due to the way the cpu connector is and the way the cpu can mounts to the board, the whole circuit board has warped over the years, and I'm sure that hasn't helped.

    I'd really like to get this TT back in working order. Cosmetically it's almost perfect - the metal lid/panel on the right has come unglued, but besides that the rest of it seems intact. Any help or advice will be greatly appreciated.

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  • 04-07-2008 5:17 PM In reply to

    Re: Seemingly dead Beogram 8000

    Hi:

    No need to start replacing cables. Why fix what's not broken? And since you haven't isolated the fault introducing additional modifications will only create additional uncertainty.

    Use the continuity function on your DVM to confirm that the there are no loose connections on the cable assembly. I've fixed a few of these things and never had any problems with the wire assembly.

    Dillen (on this group) has the re-cap kit. There is nothing special about it except that he's put one together with the right parts and a component layout diagram. This just makes things easiers. If you are in the US, you can get the caps from any local source such as Mouser or Digikey. You just have to add each one to your shopping cart. The economics is how much your time is worth!

    Start with finding/solving cold solder joints. Then recap.

    Very often pins that plug into the transformer are loose, so start with this first.

     

    Derek
     

  • 04-07-2008 5:20 PM In reply to

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

    Re: Seemingly dead Beogram 8000

    Welcome to Beoworld !

    I can supply the cap kit and it sounds like your Beogram is in need of this as a minimum, it usually fixes many faults - also some you never knew it had.
    It's in the 25 euros range with shipping.
    I wouldn't worry too much about the CPU cable or the warpage of the board. They have looked like this since they were made, unless actually damaged of course.
    Cracked solders are a problem though, check out the main board, especially around the edge connectors and in the power supply areas.

    Martin

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