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Re: Mac Classic floppy issues

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  • s100doctor
    ... I ve run a IIci for years without a PRAM battery. It boots fine, of course the date and time is incorrect. On some old Macs, you do need a good PRAM
    Message 1 of 6 , Jun 9, 2012
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      > Posted by: "Kyle Owen" kylevowen@... kylevowen
      >
      > Hi Darren,
      >
      > As it turns out, the Mac IIcx doesn't boot. The power supply seems to be
      > good, as it does have the 5V present for the continuous supply. I don't
      > know how to further test the power supply, however.
      >
      > Kyle

      Al Hartman <alhartman6@...> wrote:
      >
      > Even with a working power supply, a bad PRAM Battery will cause the unit not
      > to boot. I always check the battery as step one
      >

      I've run a IIci for years without a PRAM battery. It boots fine, of course the date and time is incorrect. On some old Macs, you do need a good PRAM battery to boot it. These batteries will leak after decades and run the motherboard - remove them if the unit is stored.

      The IIci and IIcx, among many 68K Macs, will simply die from age. That PRAM battery creates a constant current which turns copper to copper oxide (blue rust). It's just like rust on a car: wet metal is just another battery. Also, some of the components, some capacitors, break down. Also, some of the IC leads seem to rust up, possibly related to the presence of the PRAM battery.

      It's very common for the Mac II series to power up but not run, then not power up at all. The power supply depends on some features of the motherboard to "start". Power supplies will fail also, the simplest test of course is to have a known good IIci or cx or 700 power supply.

      I sell these supplies, Kyle, but even if I took it back the cost of shipping it back and forth is close to the cost of the supply. Find someone with the same Mac who is willing to swap power supplies. But chances are your IIcx is not gonna work. I have many more IIcx supplies than motherboards, for a reason.

      Herb Johnson
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