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  1. techknight

    Flyback opinions wanted

    You have to cut out the cracks and check for carbon tracking first, otherwise you are wasting your time. Then once that is clear, you then have to bake the transformer to drive out ALL moisture. At this point, you dip it in a pot of hot boiling wax and that pot is sealable. once you do this...
  2. techknight

    IIsi Fuse blows in recapped power supply?

    You do you, so if you wanna just start throwing parts at it, be my guest... but, what you demonstrate in the video is normal.
  3. techknight

    550c Screen Stain?

    No, i have not. because I have not personally encountered a machine with that problem. BUT... I do know that it will happen someday, as adhesives just naturally break down over time. it just, is what it is.. Look up 60s/70s color TVs and the PVA safety glass bond.
  4. techknight

    550c Screen Stain?

    its probably vinegar syndrome just starting.
  5. techknight

    IIsi Fuse blows in recapped power supply?

    short means .000 or close to it. That seems normal to me. You should start checking all components instead of throwing parts at it. Such as, check the main regulator for shorts. check the switching transistors for shorts, etc... Sounds like the power supply grenaded itself and thats that.
  6. techknight

    128/512/Plus 240V crowbar circuit - any ideas?

    Its possible the engineer for the international version ran into a parts availability problem, so he came up with a rather unconventional method of doing the task. And yeah you are correct about building the voltage drop at a certain point for the transistor to conduct, thus clamping the...
  7. techknight

    400k floppy drive glitchfest (flashing warning?)

    its acting like a memory out of bounds condition. like a pointer that got sent off into the weeds which just starts filling up memory with w/e, eventually hitting screen memory. So yeah, its not executing or reading the code properly.
  8. techknight

    How does a compact Mac fit into your daily lives?

    Yeah everything here is chain which is JS heavy.
  9. techknight

    SE brightness instability

    Did you spray and clean out the brightness potentiometer? Its also entirely possible the CRT is starting to develop an issue in the electron gun. Check that too.
  10. techknight

    How does a compact Mac fit into your daily lives?

    Now, how in the world did you manage to order a PIzza on that thing? I didnt think they could render the modern web to do such tasks.
  11. techknight

    Drive gear needed for an AppleCD SC

    I just rebuilt 2 or 3 of these drives and I believe i did a youtube video on them. But they were simply recaps. I haven't ran into these failures yet.
  12. techknight

    Y2K2020 Date Problem System 7

    I know Norton Utilities does, it complains about bad dates and fixes them.
  13. techknight

    SE/30 stuck at boot with raster but no cursor

    Just make sure all the lines to the SWIM, and i mean ALL of them tone back to the GLU, CPU/ROM areas. If that looks ok, then replace the SWIM.
  14. techknight

    SE/30 stuck at boot with raster but no cursor

    I was going to ask, i dont see where you specify the actual problem unless i overlooked it. Then i followed further in the thread and i wanna make sure i actually got this right: you get a chime with a raster. What raster do you get? got a pic? what chime? Death chimes or good chimes? or good...
  15. techknight

    SE or SE/30 replacement PSU / no analog board

    Portable uses a documented standard. Otherwise, youd have to pull a datasheet of the panel you are replacing and follow those specs. if neither are operable, Logic Analyzer time...
  16. techknight

    SE or SE/30 replacement PSU / no analog board

    I think it would be neat to do an FPGA project to convert LCD signaling standards from the older parallel stuff like in Powerbooks, and especially the Macintosh Portable, to put out the correct timing signals to more modern LCDs that could be used as retrofits into the old stuff...
  17. techknight

    New Hybrids for the Macintosh Portable M5120?

    I am starting this thread because we are at the point where this needs done.  I also want a record for links to other peoples projects on that so they don't get lost. I know there is one floating out there, but alas... I forgot to save the link to it.  Anyways... I have a prototype M5120 and...
  18. techknight

    Trying to identify a game from memory

    there was a game I used to play when I was a kid, but I don't remember what it was called.  I remember being inside a scene with a bar, and getting asked the question: "Choose your poison"  Trouble was, I never could get past that level because I kept typing out actual poisons which of course...
  19. techknight

    3400c backlight issue

    Here is a new one. When I last monkeyed with the 3400c I owned, everything worked fine, even the battery held a charge. I pulled the PRAM battery as it was showing signs of starting to leak. this was years ago.  I just so happened to pull it out today to recharge the battery, and check it out...