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About BadGoldEagle

  • Birthday 04/18/1996

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  • Location
    Weissach, Germany
  • Interests
    Compact Macs and post 1998 Macs (PPC and Intel)

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  1. Hi I'm currently trying to troubleshoot a 512K that has a bad 120V analog board. The display keeps cutting out every half a second or so and it makes the dreaded flup flup noise. It happened out of the blue and when it's starting to get hot. The dead Mac scrolls points to bad CR20 & CR21 Schottky diodes. I tested them but I am not getting the same results as Larry Pina... CR20 should be 31Ω/30Ω. I'm getting 107Ω/84Ω. CR21 should be 52Ω/53Ω and I'm getting 41Ω/43Ω. I got those readings by switching the red/black terminals on the multimeter between the cathode and the diode. Is that how I'm supposed to test them? Shout I try when they're hot or cold? And can you really test diodes in-circuit? Thanks!
  2. BadGoldEagle

    IIci with Maxell bomb damage

    First I‘d try to remove what’s left of the crystal. There should be a couple of solder joints on the back side (if they’re not corroded to hell that is). Then get some white vinegar and scrub with an old toothbrush until you can’t see any of the brown stuff. Be careful of the RTC chip, you probably won’t find a replacement if you accidentally damage it. Rinse with clear water or isopropanol. If you choose water, dry it up with a hair dryer afterwards. There might be a broken trace under the crystal... but again this has to be one of the least damaged Maxell victims I’ve seen. You got lucky.
  3. BadGoldEagle

    Macintosh 512k sad Mac error help

    What Bibilit said + If your other machine is a 128k, another 512k or a Plus, you can switch around the ROMs to troubleshoot. Be sure not to put them on backwards...
  4. BadGoldEagle

    Resurecting a battery damaged Macintosh Classic Logic Board

    Sorry for the late reply. D3 is indeed not listed on the schematics but there are a few instances of DP3 and DC3, which are also diodes, and more importantly they're of the same type: 1N4148. I'd go with this one instead of the 1N4001, but I'm no electrical engineer.
  5. BadGoldEagle

    SE/30 only reads write protected floppies

    I completely forgot about the SWIM on the SE/30 not being socketed... In that case I'd test the connection between every leg and its corresponding pad on the bottom or with a VIA. Alcohol can help getting rid of residues such as cap goo etc. Use a Q tip or an old toothbrush to clean the legs. A quick flock with a dental pick will more than certainly result in a lifted pad, and you definitely don't want that!
  6. BadGoldEagle

    SE/30 only reads write protected floppies

    I know this’ll sound stupid, but have you tried pulling the swim out of the socket and putting it back in? I’ve had a similar problem with one of my SEs. I thought the swim was a goner until I swapped it back and fourth with a known good one, and the defective chip started working fine again after a few tries.
  7. BadGoldEagle

    Platinum 512ke?

    1987/88 EDs (ie 512Kes for Education) sold in Germany and the Netherlands were indeed platinum with "Macintosh ED" branding on the front. There is evidence online of a 220V platinum 512Ke with no label on the front. But it could have very well started out in life as a normal "Macintosh ED" and someone could have wiped the label off with alcohol or something...
  8. You need the patched version. The vanilla one won't work with this HD. https://macintoshgarden.org/apps/apple-hd-sc-setup-753-patch I hope you have a Floppy EMU or a bridge mac to create 800k disks...
  9. I've noticed that heavy duty aux. PSUs are rather heavy. I had found a 35A 5V industrial PSU but it weighted about two pounds... What kind of amperages can your FlexATX deliver? For a IIsi, power isn't a problem.
  10. The main issue with modern PSUs is that they can't really output more than 20A on the 5V rail. The old 800 PSU could do 30A, and the Delta unit in the 9x0s could do 33A. I know they probably don't need all that power at all times except perhaps if you intend to use them as an old school server with more than 10 hard drives in them... but it's kinda difficult to know what the actual current draw is. I'd say it would be about 18A maximum to power the board and drives but I wouldn't feel very safe with a saturating cheap aliexpress PSU in my machine... For the Mac IIs or the Q650/700, modern ATX PSUs are still within the limits.
  11. BadGoldEagle

    Analog Board Recaping Advice

    Hi I wouldn't get caps from ebay or aliexpress if I were you. Most of them are probably fakes with a shiny enclosure. I'm in Europe and shipping/handling fees from sites such as Mouser or Digikey can be prohibitive. I use Arrow because they offer worldwide shipping on orders above 50 bucks (I think... don't quote me on that). 105°C caps aren't that much more expensive to be honest... try to get long life ones (typically 5000+ hours). ESR is also important, but if you get a high grade cap, it'll more than likely already have a good ESR value.
  12. BadGoldEagle

    Hate to do this but... SE/30 Help needed

    I'd remove the old caps by cutting the top with some pliers (safer as ripping them off or twisting them I think), then immerge in some hot soapy water, scrub with a toothbrush. Rinse with clear water when done and rinse again but this time with isopropanol (this will effectively make the board dry faster and prevent any rust from forming). After that, clean the pads with your iron, and start soldering the new caps on. Did you go with tantalums or electrolytics?
  13. BadGoldEagle

    Hate to do this but... SE/30 Help needed

    The vertical lines in the first picture are definitely cap related. One of my boards produced the same patten before it was recapped (oddly enough it worked great without the accelerator, it only did this with the 50MHz Powercache 030...). Don't forget to clean the board REALLY well with isopropanol once you've removed the old caps. The rest of the symptoms are probably caused by cap goo shorting out a few components.
  14. BadGoldEagle

    Macintosh Performa PSU wrong voltage

    Hi If you had faulty voltage regulators, you'd most likely have nothing at all on the 5V or the 12V rails. As ever with those old machines, caps fail. Even if they're not swollen it doesn't mean they're fine. Low voltage typically suggests weak caps, so recap first and if it still doesn't work, then we'll have to do some troubleshooting...
  15. BadGoldEagle

    Pull power supply from SE

    I’d remove the screws that hold the analog board in place, disconnect the logic board and the CRT neck board. That way you’ll be able to swing the analog board out of place without disconnecting the yoke and the flyback... giving you plenty of space to remove the PSU.