Mac M0001 booting/400k internal drive problems -- please help!

Discussion in 'Apple Collectors' started by Spookypins, Apr 7, 2018.

  1. Spookypins macrumors newbie

    Spookypins

    Joined:
    Apr 7, 2018
    #1
    I recently bought a Mac M0001 from 1984 that I wanted to try restoring. I knew the machine powered on but it didn't come with any software so I wasn't sure what I'd be facing. I assumed it was a 128K based on the model number and the fact that the badge on the back says just "Macintosh" but the motherboard is the version from 1983/84 that could be either 128k or 512k, and mine's 512k (I'm assuming this motherboard isn't original). I bought some bootable discs from Rescuemyclassicmac.com and wasn't getting anywhere -- the disc drive would take them for a few seconds and then eject them, giving me the disc/X icon. I spent a lot of time cleaning the drive as the eject mechanism was seized. Still wasn't making progress until I noticed the pressure pad mechanism wasn't moving up and down as I had seen in a video. After oiling that, I powered it on and -- success! It booted up and I start to playing around with the software that came my discs. I was out of the woods! ... for about 10 minutes.

    I had clicked on a MacPaint file and it seemed to be taking forever to open it and then I noticed a burning smell -- that can't be good. So I turned it off quickly and let it sit for a bit. After turning it back on and trying to boot from the disc that worked before, I either get the flashing disc/X icon or I get 0f00064 sad mac code -- which I had not gotten at all before. And the mechanism that moves with the pressure pad up and down the disc while reading is no longer moving again. Everything there moves freely so I don't think that's the problem.

    Any ideas what I could do? Did the ROM chips go on me? The ROM chips read:

    "ROM-LO" is "342-0221-B"
    "ROM-HI" is "342-0220-B"

    Any assistance helping this noob would be greatly appreciated!
     
  2. MacTech68 macrumors 68020

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #2
    The 0F00064 error code is a bit of loose end,

    "Couldn't Read System File into Memory or 64K ROM Mac reading a HFS formatted disk"

    Since you've used this combination of hardware and software successfully before, that leaves us with discovering why it couldn't read the system file.

    If you follow that chain, you may find the problem. Is it a 400k drive? If so, there should be felt pressure-pad that rests on the disk. I've seen them missing before. They're mounted on a round plastic holder with a twin barb clip on the opposite side.

    You may also want to blow some air into the track zero optical sensor.

    A similarthread with much more information and ROM info is right here:

    https://forums.macrumors.com/threads/400k-internal-drive-problems-f0064-error-code.1902493/

    The felt pad:

    OA-D34V-22 - Pressure Pad.jpg

    As for the burning smell, unless it is the Class X & Class Y suppression capacitors (a common fault these days), you'll need to look it over and see if you can find any excessive heat marks.

    If possible some good, in focus pics of your analog board may helpful in locating bad components.
     
  3. Spookypins thread starter macrumors newbie

    Spookypins

    Joined:
    Apr 7, 2018
    #3
    It is a 400k drive and, long story short, the felt pad is there. (Long story: When I first starting working on the drive the felt pad was not there; I fashioned a replacement out of a felt pad you'd stick on the bottom of a chair leg or something. Then later, I discovered the original felt pad insert sitting in my workspace so it fell out some time over the years and I was happy to stick that back in vs. my replacement.)

    I saw the thread with the ROM information, which was very helpful but I'm not sure if it solves my issue. My current theory is that for some reason entire mechanism with the read head isn't moving back and forth via the rotate shaft like it was before. It seems like it's struggling to move. Before it moving back and forth while reading the disc. I'm not sure if it's not moving because it can't or because something else.

    I've attached a few photos of the analog board and the drive.

    [​IMG]

    [​IMG]

    [​IMG]

     
  4. MacTech68 macrumors 68020

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #4
    I can't see much wrong, although the battery on the analog board has leaked at some point. The leads of some passive components do appear to have corroded. Worth a look at the solder side for any really badly corroded and/or blackened solder joints.

    However, before you go down that path, start with some basics like checking the power supply output voltages for the +5v and +12v rails.

    Page 8 of this handy PDF details checking the voltages:

    http://www.ccadams.org/se/classicmac2.pdf

    Another thing you can do with the floppy drive is to manually wind the head stepper motor, such that the head moves towards the center hub. Use a plastic stick of some kind to slowly rotate the shaft - tedious I know. It should rotate fairly freely without power applied. When you next apply power, the drive should wind the stepper motor, moving the head back towards the outer edge. The sound of the stepper motor should be smooth (and fairly quick). IIRC the drive will need a diskette inserted to allow the stepper motor to move when power is applied. Use a floppy disk that is NOT important for these tests.

    Resist at all costs the temptation to remove screws holding the stepper motor or track zero optical sensor. Doing so will destroy the alignment of the drive.

    The Class X & Class Y suppression capacitors on your analog board appear to be fine and are of a type that don't appear to be blowing themselves up (as yet). :)
     
  5. Spookypins thread starter macrumors newbie

    Spookypins

    Joined:
    Apr 7, 2018
    #5
    I haven't checked the power supply output voltages yet, but I did what you said regarding winding the stepper motor so the head moved toward the center hub. When I applied power and put in a floppy, the stepper motor is not moving at all. The disc spins for about 2 seconds and then is ejected. Rinse, wash, repeat. I did this about 10 times and did not get an 0F00064 code. Just kept getting the flashing disc/X icon -- and no movement from the stepper.

     
  6. MacTech68 macrumors 68020

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #6
    Did you brush and blow the dust from the track zero optical sensor ?

    OA-D34V-22_01 Optical Sensor.jpg
     
  7. Spookypins thread starter macrumors newbie

    Spookypins

    Joined:
    Apr 7, 2018
    #7
    I bought an electronics duster on the way home from work and blew air all around the 2 black cubes that I assume is the track zero optical sensor. No change: Discs spin for about 2 seconds and then are ejected. I'm no longer getting the 0F00064 code. Just keep getting the flashing disc/X icon -- and no movement from the stepper.

     

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