I ran into a Macintosh Plus which when booted makes a continuous flup flup flup sound.
This can occur if there's a voltage rail short on the logic board, floppy, or SCSI drive.
The short can cause the hidden fuse inside the power harness that goes from the analog board to the logic board to blow.
Use your multimeter to check for continuity on the blue wire between the two harness plugs (pin 6, +5V). If there is no continuity you have a blown fuse.
If your zip ties aren't too tight, you should be able to slide the clear sleeve off to the side, you'll reveal the green fuse.
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We see that this is a Littelfuse Inc. 5A fuse. A quick part look-up points this to be part number 0251005.
You can pick up a replacement at your usual places like Mouser, Digi-Key, or eBay.
This can occur if there's a voltage rail short on the logic board, floppy, or SCSI drive.
The short can cause the hidden fuse inside the power harness that goes from the analog board to the logic board to blow.
Use your multimeter to check for continuity on the blue wire between the two harness plugs (pin 6, +5V). If there is no continuity you have a blown fuse.
If your zip ties aren't too tight, you should be able to slide the clear sleeve off to the side, you'll reveal the green fuse.
enhance...
enhance...
We see that this is a Littelfuse Inc. 5A fuse. A quick part look-up points this to be part number 0251005.
You can pick up a replacement at your usual places like Mouser, Digi-Key, or eBay.
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