Home Forums Product Discussion & Questions BeoMaster Beomaster 6500 CPU

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  • #37147
    rrm
    BRONZE Member

      Which CPU does a BM6500 use (serial begins with 08)? I suspect the CPU could be defect as the BM6500 does not start up from standby. Replacing caps and battery on the CPU board did not help. Is the spare CPU still available?

      #37148
      Die_Bogener
      BRONZE Member

        The cpu is a 80C32 chip. Jep, there are still a lot of them available… but most are not compatible with the old one.

        It must be a Philips 80C32 BPN (!!!)

        Not compatible are 80C32x2 … they are working faster, there are timing problems.

        Have you checked 5V on the cpu board? Best point is the Eprom 27512… Pin14 GND and Pin28 5V.

        Was there a Service RESET done… if battery changed? (!!!) Otherwise it will not respond!

        #37149
        Dillen
        Moderator

          Could also be a Siemens SAB8032A-P or a third type I don’t recall right now.
          You will have to look inside.
          When you know the type ask at Beoparts-shop. Even if not listed, quite often old stock can
          be found there which is much better than buying asian counterfeits off Ebay etc.

          Martin

          #37150
          Die_Bogener
          BRONZE Member

            Siemens, Philips, Intel are OK.

            ATMEL is not ok. To modern…

            It must be a standard 80C32 CPU, not with extra additional ram… just 256 internal Bytes. No additional Eprom or ROM or extended RAM beyond 256bytes. No extra Timer.

            Not Atmel 80C32x2 because faster…

            I prefer Philips, just because of asian counterfeits… intel and Siemens are more expensive or some people get more of your money for nothing.

            Martin No.2

            #37151
            rrm
            BRONZE Member

              Thanks both for the expert advice. I am glad to hear that the Beomaster can likely be repaired even if the CPU has died. The Beomaster has been reset after backup battery replacement and worked for a while, yet in an unstable manner with poor IR reception, freezing (mains power off required to restart), and loss/overwrite of programmed radio stations and sound settings.

              #37152
              Die_Bogener
              BRONZE Member

                Do you have access to a datalink connection?

                I had a 8032 cpu with a defect INTerupt pin… meaning that IR is working bad. I connected the master to a MX TV-set… and all was working fine. Exchange of the cpu and the master was ok.

                But: use a good socket. It can happen again. The reason is a missing z-diode on the INT pin, causing a small overload during communication. I added a 5,6V z-diode…

                And: check the keramic caps near the connectors. There were problems with them, mechanical stress is not good for them.

                Also the connector on the front-IR board is very often corroded, causing erratic flickering of the display data.

                Martin 2

                #37153
                rrm
                BRONZE Member

                  Thank you Martin 2 for additional hints to the troubleshooting. Yes, the Beomaster could be operated via Datalink when unresponsive to the remote commands or the front panel buttons. Now when it cannot turn on from standby there is no response via Datalink either.

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