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cruff

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  1. cruff

    Apple IIGS

    Definitely remove the soldered on battery and replace it with one of those kits to mount it in a holder off-board.
  2. cruff

    Disk Errors

    It is possible that a PATA HDD is starting to develop errors by this time, and that could explain the errors and corrupted file you saw. A low level reformat might correct the issue, but finding a utility to actually do the low level format might be difficult. Obviously you would have to start from scratch to reload the HDD after that. There is a possibility that bad capacitors are causing problems also, could be anywhere in the power supply, motherboard or on the disk itself. You'd need to verify that the power supply voltages are in range and do not have large amounts of ripple on them. An out of spec voltage or ripple could also cause those types of errors. Double check that the cables are seated, oxidation on a contact could cause issues also.
  3. cruff

    68040 Insertion Force

    You could just wait and try seating it further when the chip and socket had warmed up a bit. Don't over do it so as not to crack the chip carrier. Or you could just use it and if it acts up later then try to seat it further.
  4. cruff

    SCSI2SD Performance Issue?

    On my 5.0a board, you physically remove the terminators. On a 5.1 or 6.0 board, you can do it via scsi2sd-util. On the 5.5 board, the web site says it is permanently enabled. http://www.codesrc.com/mediawiki/index.php/SCSI2SD#Technical_Specifications Note there is a comment for the 5.5 board: I don't recall if all Macs supplied the terminator power.
  5. cruff

    SCSI2SD Performance Issue?

    Is the SCSI bus properly terminated when the SCSI2SD is attached?
  6. As to the resistors for a dummy load, you'll need to calculate the appropriate values and power ratings for the load you want to draw. For example, if you want to draw 1 A continuous from the 5 V supply, you will need a 5 ohm resistance that can withstand 5 W. If this was a continuous service, then you'd likely spec a 10 W resistor or provide proper heat sinking/cooling. For your test, where you won't be running it continuously, you could get by without cooling. You could also use 5 x 1 ohm resistors in series, and you could get by with 1 W resistors as each would have approximately 1 V across each one. You might want to draw current from the other supply voltages also, to see if there are issues with regulation under load. In that case you'd add resistors between the other voltages and ground with the appropriate ratings. Are the voltages and currents marked on the supply somewhere?
  7. You can test it. Some switching power supplies require a minimum load for their regulation to work correctly. I don't know anything specific about a IIsi power supply, it's been probably 25+ years since I had a IIsi in my collection. Often for small computer power supplies, the +5V line needs some fraction of the amperage rating drawn, and the other voltages will be regulated as a byproduct. You can attach a suitable resistor across the +5V and GND lines to achieve this. The resistors might be some combination of power resistors to draw an amp or two, or possibly a automobile lamp. Since the IIsi won't supply a lot of power, and you won't be doing this for too much time at a shot, you can probably get by with some ceramic power resistors and not needing to supply cooling for them.
  8. Fuse F101 appears to be missing, but there are end caps in the fuse holder?? Was there ever a capacitor installed at C116? It's not obvious from the picture if something was there previously. Maybe C302 is leaky?
  9. cruff

    ImageWriter II blank pages

    Possibly, especially if they are part of the print head pin driver power supply. Also it would be prudent to check the cable that leads to the print head for breaks or being disconnected. This manual might be useful if you don't already have a copy. https://mirrors.apple2.org.za/Apple II Documentation Project/Books/Sams ComputerFacts - Imagewriter II.pdf
  10. cruff

    ImageWriter II blank pages

    And the print head is properly located so that if the printing pins will actually contact the paper? While it is attempting to print, can you tell if the pins are even moving? Maybe there is an issue in the circuits that drive the solenoids that actuate the pins.
  11. cruff

    Replacing the foam on an HP scanner

    If you can buy a sheet of the correct (or near correct) thickness, only cutting to width and height is necessary.
  12. cruff

    Recap gone right?

    Oops, but at least you know which one to reverse now.
  13. cruff

    Replacing the foam on an HP scanner

    Maybe you can find a suitable closed cell foam sheet used to wrap items for shipment? That could be obtained in small quantities from a packing supply store or online (but maybe in larger amounts than you need).
  14. cruff

    Quadra 700 fuzzy video

    Sounds like a bad capacitors issue. Maybe start with the power supply then move to the motherboard.
  15. Does the cable have a solid fill for pin 17 or does it have one of those removable plastic filler pins? If it is solid, then you will have to break off pin 17. If the other case, then you can remove that filler pin, but be careful to plug the cable in with the correct orientation.
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