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  • Re: Beomaster 5000 failed amplifier section

    Appreciate the advice and I appreciate the challenge. As has been pointed out, the boards are fragile and the traces lift and I had a few places I had to repair to get things to the state they are in. But now I have two amplifier boards with all visible issues repaired with darlington's removed and 3 out of the 4 channels measuring the same DC voltage everywhere I measure with my scope. I'm going to make the wild assumption that 3 are all "good" at this point since they all behave
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Tue, Nov 30 2021
  • Re: Beomaster 5000 failed amplifier section

    Yes, I did adjust the idle trimmers when I started out. And more recently, I replaced them both because they were original. The fact that the right channel BDV65B just exploded last time I had it all put together has me nervous about trying it again so I'm going slow. Can a bad transistor result in this kind of excitement or is it more likely a voltage condition going into a formerly good transistor? These darlington transistors are a bit strange since it looks like they have a resistor path
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Fri, Nov 26 2021
  • Beomaster 5000 failed amplifier section

    I have been struggling trying to get one working Beomaster 5000 working out of 3 non-working receivers. Two of them had failures in the PC board in the same trace leaving the rectifier. Must have been a design flaw in the PC board. After repairing these, and finding what I thought were 4 good BF857 (TR108/208 and TR109/209) and four good Darlingtons (BDV64B and BDV65B) I had a spectacular failure which blew the lid off of the BDV65B on the right channel along with a nice puff of smoke. I removed
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Wed, Nov 24 2021
  • Re: Beomaster 5000 - do they all fail in the same way?

    The darlington pair is BDV64B and BDV65B. Mouser has a BDV64BG which I assume works, but they are out of stock until way into 2022...
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Tue, Oct 19 2021
  • Beomaster 5000 - do they all fail in the same way?

    I am trying to repair a Beomaster 5000 that had some failures on the amplifier board. I have two others that I bought for parts. I started looking at the darlington transistors and I found that they were all bad. When I say bad, I'm saying they failed the normal "transistor test" with a multimeter on the diode setting. For example, the BDV64B (PNP transistor) showed a reading with positive on Base and Negative on Emitter. And for the BDV65Bs, I had a reading with negative on the base
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Tue, Oct 19 2021
  • Debugging fried Beogram 4002

    I managed to brick my Beogram 4002 (probably by mis-aligning the stupid plugs when putting in the main board). I want to go through the debugging process that is outlined in the service manual. The first voltages I tested with my oscilloscope ground connected to the chassis were strange. The DC voltage looked like an AC wave. Made no sense. Then I connected the ground to the black side of the main DC power capacitor (which seems to supply two DC voltages) and all of a sudden the voltages appeared
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Thu, Sep 30 2021
  • Re: Beogram 4002 Solonoid

    Hi Cliff- It is hard for me to remember, but i think the copper sleeve can be pushed out in one direction. One side is flanged way more than the other so I would try to work it out the easier way. If you want to try to replace the solenoid, my 3D design is on a website called "tinkercad.com". Search for "Beogram 4002 Solenoid" and you can find it and order one printed and sent to you. Winding the solenoid is not difficult. You can see in my photos how I did it with a drill. Just
    Posted to BeoGram (Forum) by Jeffrey P Brooks on Tue, Sep 28 2021
  • Re: Beogram 4002 won't turn off and turns itself on - Ghost inside!

    Hi Sonavor, That is okay. I managed to completely screw up my turntable by mis-connecting some of the plugs when I put the board back. now it is totally dead. The service manual has a flow chart to follow for debugging, but it would be super helpful if i had a diagram of the PC board that showed where the components live. Every other B&O service manual seems to have that, but the one that is online here does not. I have to believe that the full service manual has the fold-out orange-colored pages
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Mon, Sep 27 2021
  • Re: Beogram 4002 won't turn off and turns itself on - Ghost inside!

    Thanks Sonavor. I have found a Beogram 4002 Type 5513 service manual, but unfortunately it does not include the picture of the PC board itself with the location of these components (and testpoints). And sadly, it is almost impossible to read them off of the green back. Usually, the service manuals have a fold-out page that has pictures of all the boards on it, but that seems to be missing from the online copies of this service manual. This will be slow going!
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Fri, Sep 24 2021
  • Beogram 4002 won't turn off and turns itself on - Ghost inside!

    I recently sold what I thought was a perfectly running Beogram 4002 to someone and they sent it back because of some mysterious behavior. 1. Sometimes, when turning off, the carriage would move all the way to the right (as it should) but it would not turn off the motor. 2. Sometime it would turn off, but after sitting for a while, the motor would just start running on its own. I have the turntable back now and guess what? I can't reproduce any of this. Does anyone have an idea what might cause
    Posted to General Discussion & Questions (Forum) by Jeffrey P Brooks on Thu, Sep 23 2021
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