Sad Mac when i boot my Mac Plus.

Discussion in 'Apple Collectors' started by Vintageia, Jan 4, 2014.

  1. Vintageia macrumors newbie

    Jan 4, 2014
    Hello! I really need some help with my old Macintosh Plus. When I boot my Mac Plus I randomly get a Sad Mac. The error code is 017F9F. If I could get help, I would be eternally grateful :)
  2. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    I believe that an "01" code means that it couldn't read the ROM correctly. No idea how to fix that (if my diagnosis is even correct!)
  3. gr8tfly macrumors 603


    Oct 29, 2006
    ~119W 34N
    "01" decodes as a ROM test failure.

    There are two ROMs on the logic board, which are socketed. It's possible there's a bad connection between the ROM chip and the logic board through the socket. My own first shot at repair would be to reseat the two ROMs. It's certainly possible there's a poor connection between the ROM's pin(s) and the socket.

    Warning: Before opening and working on the Mac Plus, please research and practice the proper safety precautions required when working around CRTs and their high-voltage power supplies. They pose a dangerous and potentially lethal shock hazard - even after disconnection from mains power.

    Now that's out of the way, here are some suggestions which might fix a mechanical connection problem:

    Be sure to use proper static elimination procedures. Try to handle the chip by the package ends and avoid touching the pins.

    First, I would just try and wriggle the chip(s) in-place. Next best choice is to remove and re-insert each ROM. If you happen to have a removal tool, all the better, but in any case use care to remove the chip evenly - meaning straight up so you don't bend any leads.

    Good luck! It's fun to return to that "simpler" time.
  4. tdiaz macrumors 6502

    Feb 7, 2006
    Secondly, FWIW, once the CRT is discharged, I like to suggest removing the neck PCB from the back of the CRT before pulling at any cables on the motherboard.

    In those instances where that cable is tight, more so with the Mac SE, though I have seen the ones on the Plus type do it too.. if they've not been removed in a long time, they get stuck. People pull, lightly at first, and then more .. and more .. and suddenly it snaps off .. and the hand hits the neck PCB.

    The next thing you hear is a "psssssssssssssss".

    You've busted the nipple off the CRT and that's it. It's done.

    Once you've got your ROM issue sorted out, if your motherboard has been upgraded to 4MB but the image on the screen has disproportional borders. The top and bottom are thicker than the sides, you can take the opportunity to adjust that, using a CRT adjustment tool set. Looking on the outside of the power supply PCB, there are some diagrams printed on the white sheet. One of them has a monitor with up/down arrow diagram on it. That is the screen height. Turning it slightly while it's on, you can see what it does. Make it "look right", to where the pixels are square, and that blinking folder isn't squished, or put a disk in and let it boot to the desktop.

    There's a graphic around that shows a square box that you can use a ruler, though I just do it by looking and usually nail it.

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