Older Amiga A2000 Power supply repair

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  • roadrash
    Badcaps Veteran
    • Oct 2015
    • 490
    • U.K.

    #1

    Older Amiga A2000 Power supply repair

    My previous thread was for the later Amiga 2000 model sometimes called a B2000 but this is a early version Amiga A2000 and has a completely different Power supply. This one is also dead and so far I have replaced all the Electro caps and one IC (UA79M05). I haven't been able to track down the other IC I was going to replace if faulty. It is is marked with two numbers: "UC9432" and "7812". I cannot find any reference to what this actually is but is recognised by my tester. See the attached pics of this and Power supply with caps replaced. Can someone tell me if this is testing as ok and can identify it for me so I can get one for a spare.
    Attached Files
  • stj
    Great Sage 齊天大聖
    • Dec 2009
    • 31015
    • Albion

    #2
    Re: Older AmigA A2000 Power supply repair

    7812 is a standard 12v 1a voltage regulator.

    Comment

    • roadrash
      Badcaps Veteran
      • Oct 2015
      • 490
      • U.K.

      #3
      Re: Older AmigA A2000 Power supply repair

      Originally posted by stj
      7812 is a standard 12v 1a voltage regulator.
      Thanks that makes sense.
      Last edited by roadrash; 01-21-2017, 03:38 PM.

      Comment

      • PeteS in CA
        Badcaps Legend
        • Aug 2005
        • 3579
        • USA, Unsure of Planet

        #4
        Re: Older AmigA A2000 Power supply repair

        And the marking is (Fairchild Semiconductor logo) "UC8432". "UC" probably refers to the fab line, and "8432" means it was made in the 32nd week of 1984.
        PeteS in CA

        Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
        ****************************
        To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
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        Comment

        • Pentium4
          CapXon Be Gone
          • Sep 2011
          • 3741
          • USA

          #5
          Re: Older AmigA A2000 Power supply repair

          For something so old, I would carefully check all of the solder joints first thing to look for cold or cracked joints

          Comment

          • roadrash
            Badcaps Veteran
            • Oct 2015
            • 490
            • U.K.

            #6
            Re: Older AmigA A2000 Power supply repair

            Thanks everyone thats a 2nd success now 2 Amiga 2000's power supplies fixed.
            This has had all new caps and it looks like it may have been the 7812 regulator cos I hooked it up to by bench PSU and input'd 22v and got 17v out and it got hot in a few seconds too so ordered a new one which came today. Put it in and bingo running sweet again.

            Comment

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