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  1. androda

    Slow SPI (Half Speed) BlueSCSI DB25

    I actually don't have a RaSCSI, and might not be able to help very much. PowerBooks don't provide termination power to the external SCSI bus, so the RaSCSI has to be powered by a USB cable in this scenario to my understanding. It's a little unclear why changing the power adapter for the...
  2. androda

    Slow SPI (Half Speed) BlueSCSI DB25

    F4 and F4Lite BlueSCSI use an active termination system which shouldn't cause cross-talk when used mid chain. Some models have resistor packs that are removed to disable termination, and others use bus switch chips to move the terminator resistors out of circuit. Removing the resistors packs...
  3. androda

    Macintosh Portable resurrection (attempt) and diagnosys

    A 9 volt external power supply is too high. The power supply needs to be 7.5 volts at a current limited 1.5 amps maximum. Any higher voltage or amperage is going to start cooking the power regulator mosfet because it has to burn off the extra power as heat. The Mac Portable uses a linear...
  4. androda

    Opinions on this Macintosh Portable (sorry if wrong section)

    Sounds like more in depth work might be necessary on this poor machine. Portables really get eaten alive sometimes.
  5. androda

    Quadra 650 - but no luck with BlueSCSI

    If you have a multimeter, check the voltages on either side of both diodes. This will tell us whether the terminator is getting enough voltage.
  6. androda

    Quadra 650 - but no luck with BlueSCSI

    Sitting on grey screen with no other life signs sounds like a termination issue to me. Also given that this particular unit works on other machines. Is this one of Eric's V1 designs? If the termpower line in the SCSI cable is low, it will not provide enough voltage for termination to...
  7. androda

    Mac Portable Hybrid: combine forces?

    Yes, this project has been in progress for a little while now. The prototyping PCBs (with holes for resistors instead of SMD pads) were made last month, and finally found time to put them together last week. I went a little overboard and made a two-PCB system. There's the hybrid PCB with same...
  8. androda

    Powerbook 145B on order!

    It's definitely a better idea to replace capacitors as soon as possible. If there's capacitor fluid present on the board, running an electric current through the traces will cause the fluid to actively eat away the copper. Due to this literal electrolytic effect (they are called electrolytic...
  9. androda

    Which Powerbook 180 caps shoud I replace?

    Sure. These flex cable recreations are what I do with spare time, so they can take a little while to complete.
  10. androda

    Which Powerbook 180 caps shoud I replace?

    As I recall, the 180 is all tantalum on the motherboard, not sure about the display. The backlight control and inverter board almost certainly has an electrolytic.
  11. androda

    Which Powerbook 180 caps shoud I replace?

    Maybe. Flex cables are pretty expensive though, on the order of $20 per cable as the raw manufacturing cost (set of 5, plus shipping), so it would be good to have a few people that want one before doing a test run.
  12. androda

    Which Powerbook 180 caps shoud I replace?

    If trying the bodge wire doesn't work out, I'd be interested in the cable for duplication purposes. Display flex cables like these are starting to crack and die, so we need to be making new ones. I've had success with one cable so far, looking to do more over time.
  13. androda

    Macintosh Portable M5126 Weird Problem

    Very much so, unfortunately. On the backlit portable, power manager chip is the primary point of failure. There are not really any replacement chips available, and no one has created a replacement yet. The backlit portable's power manager chip connects to the VIA in basically the same way the...
  14. androda

    Powerbook 145b

    Here's hoping the screen capacitors have been replaced - they eventually go bad and then cause a solid black screen. I like the looks of the 1xx series powerbooks. Those and the Wallstreet G3 are my favorite.
  15. androda

    Need help deciphering my Macintosh Portable Sad Mac Code

    To me this looks like a possible combination of error codes. The 00001FFA makes me think it could be related to the interrupt (NMI) lines, like this Reddit person mentions: Check IPL0, IPL1, and IPL2 on the mac portable schematic, check that they connect properly. If something's wrong there...
  16. androda

    LC/LCII Power Supply Replacements?

    I'm going to make these in an RoHS compliant manner, so theoretically could ship internationally. Started laying out the PCB this morning, not sure how long it'll be until completion because kids and life stuff.
  17. androda

    LC/LCII Power Supply Replacements?

    This is a problem I'm working on. The MacTX_LC was released into the public domain awhile back. It uses one of those picopsu things to replace your original LC through Q605 power supply. I had a batch of prototype boards made and then realized it's only using the picopsu for 5v rail. My plan is...
  18. androda

    New Hybrids for the Macintosh Portable M5120?

    As a next step to my suggestion about reusing the backlit portable's non-hybrid setup, I spent an hour or two tracing it out and recreating in kicad.  This comes from a backlit portable which I just recently replaced capacitors on.  Quite happily, it works fine now. Here's a picture from my...
  19. androda

    Androda's random finds

    Cool find of the week: a nice set of Newtons.  130, Apple 2000 (upgraded to 2100), and Newton Technology 2100.  Includes one rechargeable battery (not likely to work), the AA battery cage, windows Beta version of the newton connection tools, original box for the 2000, some carrying cases, and...
  20. androda

    New Hybrids for the Macintosh Portable M5120?

    The repo I know of with information on the hybrid is here.  Might be the one you're thinking of. https://github.com/ppieczul/macintosh-portable Makes me wonder whether the backlit portable's system could be reverse engineered and used instead.  Obviously we lack the schematic on the backlit...