Powerbook FSTN display cable repair - unexpectedly works!

Daniel Hansen

Tinkerer
Oct 29, 2021
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Last week I was attempting to swap a good Rev. C passive matrix display from a parts 160 to a 145 that had a damaged Rev. B passive matrix display. Because I'm a reckless idiot, I let the display fall over while it was still connected. Of course the display cable ripped clean in half near the hinge, like dry parchment.

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Since the cables between Rev. A / C and Rev. B displays are not interchangeable, I decided to try and fix the ripped cable. If it didn't work, it didn't matter. If it did work, then cool. I decided the easiest route to take was to replace the narrow dog leg with wires, soldering to the larger traces instead of trying to mend the tear. So I trimmed off the dog leg, then used a scalpel to scrape off the mask of each trace. I then tinned each exposed trace to make pads.

I used an old USB cable for as a source for thin, insulated, stranded wire - since I don't have any small gauge stranded jumper wire handy. I measured the wire to match the dog leg, then trimmed and tinned both ends of each wire. I soldered one end of each wire to the connector, fed as many as I could through the ferrite core (not all would fit), then soldered the other ends.

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A quick test confirmed it worked.

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To lock everything down, I coated all soldered connections (and any exposed wire) with epoxy overcoat. I then started fitting everything back together. It's a TIGHT fit, but everything does indeed fit....

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(I noticed after taking the pic I put the 160's clutch cover on... I've since swapped in right one.)

I honestly didn't think this was going to work, as there really isn't a lot of room for much more than a flat flex cable around the hinge assembly. I'm a little nervous opening and closing the display, but so far it's working just fine. But if any cable recreations pop up, I'll be grabbing a few.
 
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Kai Robinson

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Sep 2, 2021
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If you have the original cable, can you scan it in / map the pinouts? I might be able to recreate these cables in sprint layout, and then these can be made as a flex pcb by someone like PCBWay.
 
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Daniel Hansen

Tinkerer
Oct 29, 2021
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If you have the original cable, can you scan it in / map the pinouts? I might be able to recreate these cables in sprint layout, and then these can be made as a flex pcb by someone like PCBWay.
Oh, that would be lovely. I'll have to take apart another machine to get the cable, but that won't be an issue. It might take me a few days to get around to it, but I'll DM you the images and measurements. It's a very simple cable, as you can see.