SE/30 ROM replacements issues + power cable connector name

GondolinOnMyMind

New Tinkerer
Mar 14, 2023
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All,

I got a new Purple ROM SIMM for my SE/30. I have quite some issues with that combination. The ROM SIMM itself works ok, as tested in a IIci. But apparently when inserted in that SE/30, the computer freezes at "welcome to Macintosh" and the boot process goes that far only if I manage to hold the SIMM in just right position with my fingers. If I use rubber bands or 3d-printed support clips, I get checkered screen at startup.
Now I would ask for pointers and ideas how you guys have succeeded to support the the SIMM permanently so that the digital board can be put back in the chassis.

3d clips https://www.printables.com/model/35592-macintosh-se30-rom-clips

And to ease the testing, I would like to extend the power cable to digital board. What is the connector called?
 

Elemenoh

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Oct 18, 2021
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And to ease the testing, I would like to extend the power cable to digital board. What is the connector called?
To answer your question directly it's a Molex MiniFitJr 14-position, but that doesn't matter. Just get an ATX extension cable which will fit fine. You can trim it if you like or just let it hang over one end.

Screenshot 2023-07-12 at 3.05.22 PM.png
 

JDW

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Sep 2, 2021
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I would like to extend the power cable to digital board. What is the connector called?
I show how to make such a cable in my video here...


Not sure who's ROM SIMM you have. I have a purple colored ROM SIMM from @Kay K.M.Mods , and they come in black and red too:


I've actually been doing some prep work on a new video that focuses on the CayMac Programmer, which I confirmed can program Kay's ROM, the BMOW ROM-inator II, and others...


I had issues with the thinness of the BMOW ROM-inator II MEGA (no longer sold) in my SE/30, which was one of the first non-stock ROMs (other than Apple ROMs like the IIsi, IIfx, etc.) that I tried. Rubber bands help but are unreliable and break over time. I also tried the custom made paper-clip trick, and I even tried adding solder to the pads, but those tricks too proved unreliable. I too thought about ROM clips, but then I asked my good friend Kay Koba if he could swap out the ROM SIMM Socket, since he has a Hakko Desoldering Station. He did the swap, and the thinness issues vanished. Basically it comes down to the curvature of the SE/30 motherboards (warping over time), and the SIMM socket itself.

Clips might work, but I've never tried them.
 

GondolinOnMyMind

New Tinkerer
Mar 14, 2023
17
4
3
To answer your question directly it's a Molex MiniFitJr 14-position, but that doesn't matter. Just get an ATX extension cable which will fit fine. You can trim it if you like or just let it hang over one end.
Thanks. I know that an atx-extension works, but I also like to know details like this.