possible obtronix PCB error

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Joined: Jun 5 2008 - 07:26
possible obtronix PCB error

Hi folks,

From the posted high res pictures, it appears that the 74154 is not properly grounded. This is the 24 pin DIP at the center of the board. Pin 12 should go to ground according to the data sheet. Can someone with a actually board check this out?

Regards,
Mike Willegal

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Last seen: 7 years 11 months ago
Joined: Apr 12 2006 - 23:01
75154 Ground

Mike,

I was able to see the trace to ground on a bare board using a magnifying glass. It's short, but it's there.

John Calande

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Last seen: 7 years 11 months ago
Joined: Apr 12 2006 - 23:01
PCB Error DOES exist on NON-kit distributed board

Hey guys,

I was wrong, I was looking at the KIT board and pin-12 of the 74164 is grounded.

HOWEVER, on the second board that I have, which was NOT sold as part of the kit, pin 12 is not grounded. There is also another bug on this board which M.Willegal found recently, and that is on D-7 74166, pins 7 and 10 should be connected and they are not.

John Calande
http://apple1computer.blogspot.com/

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Last seen: 7 years 11 months ago
Joined: Apr 12 2006 - 23:01
74161 not the 74166

Pins 7 and 10 should be connected on D-7 74161
not the 74166 as I incorrectly mentioned.
Sorry for the confusion.

John

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