Like all of the other components of the Macintosh IIsi, the logic board requires no tools to remove.


No parts required.

Start by turning the computer around, and remove this #0 Phillips Screw.
  • Start by turning the computer around, and remove this #0 Phillips Screw.

  • There may or may not be a Phillips #0 screw here, depending on whether or not the computer has ever been serviced.

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Now lift these two clips, and slowly pivot the case up.
  • Now lift these two clips, and slowly pivot the case up.

  • You can now seperate the top of the computer from the rest of the machine.

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  • The Macintosh IIsi's hard drive is located ajacent to the ram and floppy drive.

  • Start by pushing these two tabs out, and lifting the drive up.

  • Then, flip the drive over, and remove the connection cables.

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  • The hard drive: A Quantum ProDrive LPS, made in 1990, and surprisingly, it still works!

  • This drive has an 80MB capacity, not very large by today's standards, but not bad way back then...

  • Believe it or not, hard drive construction hasn't changed much in the last 20 years. Other than a few new interfaces, the form factor, 3.5" width and 4-Pin 12V/5V power connector has stayed the same.

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  • The "SuperDrive" is mounted similarly to the hard drive, and positioned right next to it.

  • Push these two tabs out, and lift the drive up.

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  • Flip the drive so it is on top of the power supply, and remove the "Red-Ribbon" cable.

  • 1.44MB floppy drives need a ribbon cable with a red stripe on one side. 400KB floppy drives use a ribbon cable with a yellow stripe on one side. 800KB floppy drives can use a red, or yellow striped cable.

  • This drive was manufactured by Sony in 1990.

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  • The fan recieves power from two contacts on the logic board and has no connector.

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  • In all of the years that I have worked on this machine, I have found no good way to remove the fan.

  • The best way to start, is to push in here on the side of the fan.

  • Being careful not to exert too much force, try to push in, and wiggle the fan outward as such. (2nd Photo)

  • You can now lift the fan all the way out, and remove it.

  • The Fan Power Contacts on the Logic Board:

There is no need to pull out the fan. Just take a knife and you can squeeze the tab in step 7

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  • To remove the power supply, squeeze these two tabs and lift the front up.

  • On the back of the power supply, there is a tab that also must be pressed to remove the power supply fully. You can then lift it out all the way. A firm tug may be necessary to seperate the power connector.

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  • Information on the power supply:

  • It was made by Sony in 1990, and uses a 10-Pin power connector.

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  • The logic board is designed in a way, where it can be slid forward, then lifted out.

  • To remove the board, push these two tabs outward, and begin to slide the logic board away from the back (Port Side) of the computer.

  • Once the logic board clears the ports it can be lifted out.

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  • The Processor: 20Mhz Motorola 68030 model # MC68030RC20B

  • The Onboard RAM: 1MB Soldered the the logic board.

  • RAM Slots: 4 30-Pin DIMMs installed in pairs.

  • ROM SIMM Slot: If your computer doesn't have one if these (and it works) , it doesn't need one. If it has one, it needs it in order to boot.

  • PDS Slot: For Attaching a riser card containing a math co-processor. A PDS card can then be plugged into the riser card. PDS - Processor Direct Slot

  • Power Supply Connector: for direct connection to the power supply.

  • "VSLI" chip: This machine's equivalent of a "Northbridge" It manages RAM, PDS, and the external ports.

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To reassemble your device, follow these instructions in reverse order.

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Chris Green

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