Portable Misc - Hinge clip fix, Earlier features, Super Static memory

David Cook

Active Tinkerer
Jul 20, 2023
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Broken Corners

I've seen enough broken cases that I lean toward being pragmatic rather than attempting a pristine repair. A common fracture is on the middle sides where the screen's hinge clips are secured. I usually can recover the broken pieces during disassembly. In this case, a broken-off corner was missing completely. Using its broken twin from the opposite side as a model, I took a scrap piece of ABS and milled it to mimic the dimensions. (My 3D printer is packed away somewhere in the basement).

Milling-machine.jpg


After cutting a chunk free from the larger scrap, I used a metal file to carve away the profile to match the broken corner. As you can see below, my handwork isn't a perfect match, but it is definitely good enough to be functional. Gorilla epoxy firmly attaches and fills the gaps. I post this to demonstrate that sometimes you can use what you have lying around.

Screen-hinge-clip-slot.jpg


Early M5120 Differences?

I noticed a couple of things while working on a 5120 from December 1989. I'd be interested in hearing from people that have Portables manufactured in September (or earlier).

First, the ROMs have odd labels. (Aside, yes this board needs an ultrasonic bath.)

Highly-professional-ROM-labels.jpg


Second, the cable pulls for the keyboard and trackball are made of a weak stretchy plastic.

Trackball-cable-pull.jpg


Apple upgraded to a tougher material in later production.

Heavy-duty-cable-pull.jpg


Lastly, the molded clip for the power cable is missing.

1781476450464.jpeg


It should look like this.

Power-cable-clip.jpg



Technology Works Super Static

I received a Portable with this 1 MB memory card. However, it doesn't seem to work. There aren't any errors -- it just isn't recognized. The circuitry lacks any sort of PAL/GAL. Any ideas on what's wrong?

1781476578043.jpeg


Technology-Works-Super-Static-1-back.jpg


- David
 
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JDW

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Gorilla epoxy firmly attaches and fills the gaps.
What specific part number of Gorilla epoxy did you use?
And, have you tested how strong the bond is to polycarbonate?

I used DCM to weld the broken hinge when I did my repair (which is a different part than what you repaired). But the key difference is that my break was clean without gaps, while yours appears to have gaps. DCM melts the pieces together for a very strong bond, but it won’t do gap filling at all. DCM is also rather toxic and not so fun to deal with.

I’m mainly curious about your choice of epoxy for plastics because I’ve been using J-B Weld Plastics Bonder 50133 for my PowerBook 165c and 180c standoff repairs (which I’ve been showing on YouTube), and for that application it has worked OK so far. My big issue is that I can't buy from Amazon Japan all the same epoxy brands that you guys in the USA get access too, although there are various Gorilla brand epoxies on Amazon Japan here:

 

David Cook

Active Tinkerer
Jul 20, 2023
246
318
63
What specific part number of Gorilla epoxy did you use?

I use this:

have you tested how strong the bond is to polycarbonate?

It seems genuinely strong. I know the true test is whether the part breaks at the bond site or on a new break at some other location on the original plastic. But, obviously we don't want to perform that test. : )

I wasn't sure that this really was polycarbonate as it doesn't seem tough enough. I had a scrap piece which shows the following characteristics:
1. Melts (not burns) when heated: Yes
2. Sinks (not floats) in water: Yes
3. After being lit on fire, it self-extinguishes (doesn't keep burning on its own): Yes
4. Color of flame: Orange
5. Color of smoke: Black and sooty.

That matches polycarbonate. Do you have a primary source that says it is polycarbonate, or did you deduce it?

- David