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Missing capacitors on Umax Gemini secondary CPU card

Forums > Vintage Apple > Macintosh > Clones & Conversions

Branchus
Administrator
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Joined: Sep 2, 2021
Posts: 237
Likes: 518
Nov 19, 2021 - #1
Hello all,

I have a Umax Gemini secondary CPU card (604e 250MHz) but it's been through the wars and lost a few surface mount electrolytic caps. If anyone has one of these and can tell me what sort of caps I'm missing, or a picture of one that I can use as a guide, it would be greatly appreciated!

Attachments:
gemini.jpg [View]

Liked by Mac84

Branchus
Administrator
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Joined: Sep 2, 2021
Posts: 237
Likes: 518
Nov 19, 2021 - #2
I haven't had it under the microscope yet, but at a glance, it looks like the missing resistors are meant to be that way. I think the only components that were deliberately removed are the surface mount electrolytics.

alxlab
Active Tinkerer
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Joined: Sep 23, 2021
Posts: 293
Likes: 323
Nov 19, 2021 - #3
I'll take a wild guess and say it's probably 47uf 16v or 100uf 16v. The Apple 604e 200Mhz card (630-2508-A) I got seems to be using 47uf 16v on the caps I can see without taking off the heatsink.

Liked by Branchus

alxlab
Active Tinkerer
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Joined: Sep 23, 2021
Posts: 293
Likes: 323
Nov 19, 2021 - #4
This has the same layout as mine:


Source: https://commons.wikimedia.org/wiki/File:Apple_820-0849-A_PowerMac_Processor_Card-8074.jpg

I'll keep on looking to see if I can find anything else.
Attachments:
1637345135314.png [View]

68Krescue
New Tinkerer
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Joined: Jun 23, 2022
Posts: 16
Likes: 7
Feb 17, 2023 - #5
Here is my Umax primary 604e 225MHz. These cards need to team up in a in a Supermac S900, if possible....... Would definitely make a great video!
Attachments:
tempImageJHl7wR.png (4.8 MB)

Liked by Kai Robinson

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