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MacAttack

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Everything posted by MacAttack

  1. MacAttack

    Free Macintosh Plus!

    Page 24 of the Dead Mac Scrolls also says to replace component CR20 on the board, right next to CR21. This component is an MBR1045 Schottky Rectifier Diode. In fact, pages 20 through 29 deal with this issue entirely. You didn't mention these steps so I thought I should point them out. Also, if you deduce that the flyback is the issue I could possibly send you one.
  2. MacAttack

    Macintosh 128k Help

    So, I posted here about a year ago about a 128k Macintosh that I got off of craigslist. Since then I figured out that the ram was bad and replaced it. I've got to a point where the computer functions but the video has a major issue. I have been unable to find the issue so far, so here I am again! For further reference, I do have logic probes and an oscilloscope at hand if that helps fix the issue. (Before Ram Replace) (After Ram Fix)
  3. MacAttack

    Macintosh 128k Help

    Probably not, I already replaced the MUX chips with brand new Motorola chips but this next chance I get I'll test them with my logic probe to see if I scorched the chips while soldering.
  4. MacAttack

    Free Macintosh Plus!

    I don't have much experience as my Plus only needed a ram replace, but my 128k came from a guy who replaced the analog board due to a bad flyback transformer. Now, I know that these flyback transformers are known to go bad so I wouldn't be surprised if that was causing your issue. If this is the case, then the flup noise could be the flyback repeatedly arcing internally.
  5. MacAttack

    Macintosh 128k Help

    Here, I photoshopped about where the mirrors are occurring.
  6. MacAttack

    Macintosh 128k Help

    Yea, Everything appears to be mirrored three times, one on the right, one in the middle and one on the left.
  7. MacAttack

    Macintosh 128k Video Problem

    So I want to replace the ram. I thought these chips would work. Any objections? https://www.jameco.com/z/4164-150-Major-Brands-64KX1-DIP-16-DRAM-150NS_41662.html?CID=GOOG&gclid=EAIaIQobChMI4JOMn5T02QIViV5-Ch09NgcCEAQYASABEgJPYfD_BwE
  8. MacAttack

    Macintosh 128k Video Problem

    Hello, I recently bought a 128k Mac (non-functioning) and the seller told me that he thought that the 74F253 Ram Multiplexers were bad. But after replacing them with new Motorola ones, the screen still has the same issue. Here is a photo: I have no idea where to got from this point and a google search came up inconclusive. Please Help!!
  9. MacAttack

    Macintosh 128k Video Problem

    No, not myself so I guess it could be bad ram, but I'm just going off what the seller said. Anyways, I will test the Mac Plus board in it too.
  10. MacAttack

    Macintosh 128k Video Problem

    The ram has been socketed and replaced so I ruled that out and the Mac plus board is not compatible with the 128k case
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